delivered the opinion of the Court.
This is an appeal from the decree of the circuit court of the district of Columbia, sitting at Washington, upon a bill in equity, in which the appellants were original complainants.
On the 7th of May 1822 congress passed an act to authorise and empower the corporation of the city of Washington, in the district of Columbia, to drain the low grounds on and near the public reservations, and .to improve and ornament certain parts of such reservations. By that act the corporation were among other things to change, by contract with the proprietors of the canal, the location of such parts of the canal passing through the city as lay between second and seventh streets, west, into such course as.should most effectually, in their opinion, drain and dry the low ground lying on the borders of Tiber creek; and to effectuate.this object, the corporation were further authorised; after having extended the public, reservation designated on the plan of the city as number ten, so as the whole south side should bind on the line of Pennsylvania Avenue, and after having caused to be divided the said public reservation number ten, and also the public reservations numbers eleven and twelve into building lots; to sell and dispose of the right of the United States of, in, and to, the said lots, or any number thereof, laid off as aforesaid, at'public sale; &c. &c. And the corporation was further authorised to cause to be laid off, in such manner as the president should approve, two squares south of Pennsylvania Avenue, &c.; and also to lay off north-of Maryland Avenue, two uniform and correspondent squares; and the said four squares, when so laid off, to divide into building lots; and to sell and'dispose of the *276right of the United States in such lots, &c. &c. The proceeds of these sales were in the first place to be applied to the purposes above mentioned, and in the next place’to inclosing, planting, or otherwise improving certain public reservations, and building certain bridges, &c. &c.; and the surplus, if any, to go into the national treasury. The sixth section of the act then provides, “ that it shall be lawful for the legal representatives of any former proprietor of the land directed to be disposed of by this act, or persons lawfully claiming title under them, and they are hereby permitted and authorised, at any time within one year from the passing of this act, to institute a bill in equity, in the nature of a petition of right, against the United States, in the circuit court for the district of Columbia, in which they may set forth the grounds of their claim to the land in question.” The seventh section provides for the service of process, upon, and the appearance of the attorney general, &c. The eighth section provides, “ that the said suit shall be conducted according to the rules of a court of equity. And the said court shall have full power and authority to hear and determine upon the claim, of the plaintiff or plaintiffs, and what proportion, if any, of the money arising from the sale of the land hereby directed to be sold, the parties may be entitled, to” The ninth and last section of the act provides for an appeal to this court.
The plaintiffs-filed their bill in the present case within the time prescribed by the act, making the United States and the corporation of the city of Washington parties. They claim title to the lands in controversy, which have been laid off into lots for sale, under David Burns, one of the original proprietors of the city, and of whom the plaintiff Marcia is the only daughter and heir. These lots embrace part of the reservations above referred to, and also a part of the street called B, according to the original plan of the city. The ground of the bill is, that by the original contract of the government with the proprietors, upon the laying out of the city, these reservations and streets were for ever to remain for public use, and were incapable, without the consent of the proprietors,-of being otherwise appropriated or *277sold'for-private-use; that.the .act of 1822, authorising such sale-, is.a violation of the contract; that by such sale or-appropriation for. private use, the -right of. the United States thereto was determined; or that the original proprietors-reacquired a right to consider them in the same predicament as',if originally laid out for- building lots; or that, at all events, they were entitled, in equity, to the whole or a moiety of the proceeds of the sale, if the act of 1822 were valid for th,e purposes, which it professed to have in view.
Some-difficulty has arisen at the argument, from the peculiar structure of the bill; it professing in some parts to seek relief under .the act of 1822, and in other parts insisting upon a title inconsistent with it; and demanding an injunction to prevent all sales of the 1'arrd by the corporation. The opinion of this court certainly is, that under the act of 1822; the plaintiffs can proceed by a bill in equity in the nature of a-petition of right against these the United States only for the money arising from the sales; and cannot claim a decree -for the land itself, or for any injunction against sales of it.
The view, however, of the case which we are disposed to take, renders it unnecessary to consider whether the bill is so framed that with reference to the act of 1822 the court could pass a definitive decree against the United States upon it, from the incongruities alluded to.
As it is manifestly the interest and desire of all the parties to hatfe an opinion upon the. merits, so as to put an end to the controversy; we shall waive all'consideration of .minor objections, and proceed at once to the consideration of the substantial ground of the claim.
Congress,. by. an act. passed-on the 16th of July 1790, provided that a district of territory not exceeding, ten miles square, to be located as therein directed, on the river Potomac, at some space between the mouths of the eastern branch and Conogocheague.be,. and the same was thereby accepted for the permanent seat of the government of the United States. Three commissioners were by the same act to be appointed, to survey, and by proper metes and bounds to define and limit th% district; and they werq authorised to purchase or accept'such quantity of land on .the eastern side *278of the said river, within the said district, as the president should deem proper for the u$p of the United States; and according to such plans as the president should approve, the commissioners were to provide suitable buildings for the accommodation of congress, and of the president, and for the public offices of the government of the United States. A subsequent act, passed on the 3d of March 1791, authorised some alterations of the limits of the district. Suitable cessions of the jurisdiction and soil of the territory, subject to the private rights of property of the inhabitants, were made by the states of Maryland and Virginia(a). And the former act further provided for the removal of the seat of government to the. district on the first Monday of December 1800. The limits of the district were accordingly ascertained and defined; as made known by the proclamations of the president of the 24th of January and the 30th of March 1791.
As yet no public designation had been made of the site of the federal city, which was contemplated to be laid out within the limits of the district, nor of the places on which the public buildings should be erected; nor indeed had there been any purchase or donation from any of the proprietors of lands within the district, by or to the commissioners for. that object. There cannot however be a 'question that various negotiations had been entered into with the proprietors, and informal proposals made by them with a view to obtain so important and valuable a boon as the location of the city within the boundaries of their estates. And it can admit of as'little question, that preparatory steps had been taken on the part of the government, to procure suitable plans for the laying out of the metropolis.
In this state of things nineteen of the proprietors of the land constituting the present site of the city of Washington, among-whom was David Burns, on the 30th of March 1791, entered into an agreement, which was presented totl.C com*279missioners as the basis of the terms on which they were willing to dedicate their lands for the location of the city. The agreement was accepted by the commissioners, and recorded in their books, If is in the following terms. “ We, the subscribers, in consideration of the great benefits we expect to derive from having the federal city laid off upon our lands, do hereby agree and bind ourselves, bur heirs, executors, and administrators, to convey in trust to the president of the United States or commissioners, or such persons as he shall appoint, by good and sufficient deeds, in fee simple, the whole of our respective lands, which he may think proper to include within the lines of the federal city, for the purposes and on the conditions following. _ The president shall have the sole' power of directing the federal city to be laid off in what manner he pleases. He may retain any number of squares he may think proper, for public improvements or other public uses; and the lots only which shall be laid off, shall be. a joint property between the trustees in behalf of the public and each present proprietor. And the same shall be fairly, and equally divided between the public and the individuals, as soon as may be after the city shall be laid off. For the streets, the proprietors shall receive no compensation ; but for the squares or lands, in any form, which shall be taken for public buildings, or any kind of public improvements or uses, the proprietors, whose lands are taken, shall receive at the rate of twenty-five pounds per acre, to be paid by the. public.” There are some minbr arrangements as to growing timber, and grave yards, &c., which are not necessary to be mentioned. It is material, however, to observe, that no time or mode of payment is prescribed in the agreement of the twenty-five pounds per acre; and no fund out of which'it was to be paid is designated. The agreement was merely preparatory, and to be carried into effect by formal conveyances.
Now, it is’ upon the terms of this agreement that the plaintiffs assert their title to relief in the present case. They contend, that though the whole land was to be conveyed, yet the portion of it which should be taken for streets and public reservations, according to the plan approved by the president, was clothed with a perpetual .condition or trust that *280they should for ever remain streéts and public reservations* and never should be liable to be appropriated to any private, use'; or changed from their original public purpose'.. That upon any such change or appropriation the title reverted to the'original proprietors, of at all events, was to be disposed of and divided between them in the inannerprovided for, in respect to the land laid off into lots.. They also contend,'that the' land so devoted to streets and public reservations,.was a mere donation from-the proprietors, and riot a-purchas'd-by the United States; and therefore ought.to be governed*, 'by' the rules applicable to public charities, and the trust strictly construed and enforced.
It is not very material, in otir opinion, to decide whatwa’Stbe technical character of the grants made-to the- goverfi¿flient; whether they are to be deemed mere donations or purchases. The grants were made for th'e foundation of .a federal'city; and the public faith was necessarily pledged when the grants were accepted to found' such city. • The very agreement to found a city was of itself a most valuable consideration for' these grants. . It chahged- the natuffe arid value of the property of the proprietors to an almost incalculable extent. The land was nti longer io bé devótéd to mere agricultural purposes ; Brit acquired the extraordinary value of city lots. In. proportion to thh success of the city would be the enhancement of this value; and it required scarcely any aid from the imagination to foresee, -that -this act of the government would soon convert the narrow income of farms into solid opulence. The proprietors so considered it. In this very agreement they state the motive of their proceedings, in a plain and intelligible manner. It is not a mere gratuitous donation from motives of generosity, or public spirit; but in consideration of- the great benefits they expect to derive from, having the federal city laid off upon their lands. For the streets they were to receive no compensation. Why 1 Because those streets would be tifas much benefit to themselves, as lot holders, as to the public. They were to receive twenty-five pounds per acre for the public reservations; “ to be paid” (as the agreement states it) “ by the public.” They understood themselves then to *281receive payment from the public for the reservations. It makes no difference, that by the subsequent arrangements they were to receive this payment out of the sales of the lots which they had agreed to convey to the public, in consideration of the government’s founding the city on their lands. It was still contemplated by them as a compensation ; as a valuable consideration, fully adequate to the. value of all their grants. It can, therefore, be treated in no other manner than as a bargain between themselves and the government, for what each deemed an adequate consideration. Neither considered it a case where all was benefit on one side, and all sacrifice on the other. It was, in no just sense, a case of charity; and was never so treated in the negotiations of the parties. But, as has been already.said, it is not in our view material, whether it be considered as a donation or a purchase; for in each case it was for the foundation of a city.
And in construing this agreement, this fact should never be lost sight of. It is obvious, that the proprietors or their heirs could not be presumed for any great length of time to have any interest in the streets or public reservations beyond that, of other inhabitants. If the city became populous, the lots would be sold and built upon, and in the lapse of one or two generations, at most, the title of the original proprietors might well be presumed to be extinguished by sales or otherwise; so that the interest of themselves or their heirs in.the streets and reservations would not be distinguishable from that of other citizens. They must also have contemplated that a municipal corporation must soon be created to manage the concerns, and police, and public interests of the city; and that such a corporation would and ought to possess the ordinary powers for municipal purposes, which are usually confided to such corporate bodies. . Among these are certainly the authority to widen "or alter streets, and to manage, and in many instances to dispose of public property, or vary its appropriation.
They might, and indeed must; also have placed a just con-, fidence in the government, that in founding the city, it would do no act which would obstruct its prosperity, or interfere with its great fundamental objects or interests. It could *282never be supposed that congress would.seek to destroy what its own legislation had created 'and fostered into being.
On the other hand, it must have been as obvious, that as congress must for ever have an interest to protect and . aid the City, it would for this very purpose be most impolitic and inconvenient to lay any obstructions to the most free exercise of its power over it. The city was designed to last in perpetuity : capitoli immobile saxum. No human foresight could take in the great variety of events which might render great changes in the plan, form, and locations of the city indispensable for the health, the comfort, and the prosperity of the city. Cases might easily be imagined, as in other cities, where the desolations of fire have made alterations in the streets and public squares of a city, most important and' valuable to the whole community. A. prohibition, which should for ever close, up the legislative power of congress, on such a subject, under all circumstances, ought not lightly to be presumed, nor readily admitted. It should be proved by the most direct and authentic documents, before we should admit the belief that the wisdom of the first president of the United States yielded up such a valuable franchise.
If the case had stood solely upon this preparatory‘agreement, as an executory contract, there might have been stronger grounds to impose limitations upon the grant of the streets and public reservations. The language of the instrument is, that the president may retain any number of squares he may think proper for public improvements, or other public uses. Yet even then, the appropriation of these squares for public uses would not necessarily carry with it an implied obligation that they should for ever remain dedicated to those uses, and to none other. If such had been the intention of the parties, we should naturally expect to find there some direct expression of it, some acknowledgement of the obligation, or some condition carrying it to such a political mortmain. If the stipulation was so important and valuable as is now contended for, and constituted an object of permanent solicitude, it would scarcely escape the notice of the proprietors in laying down the fundamental basis of their cessions. If it did then escape them, we *283should have reason to look for its incorporation into the more solemn instruments which were contemplated thereafter to be' executed by the parties, and were in fact executed by them in fulfilment of their original agreement. But no such stipulation is there tobe found.
On the 29th June 1791, the proprietors severally executed deeds of indenture to consummate the agreement of the preceding March. They are all in the same form, and contain the same declarations of trust. That executed by David Burns conveys to Thomas Beall and John M. Gantt (the trustees designated by the president) all the lands of the proprietor within the bounds of the city upon the following trusts, viz. “ that all the said lands, &c. as may be thought necessary or proper to be laid out together with other lands within the said limits for a federal pity, with such streets, squares, parcels and lots as the president of the-United States, for the time being, shall approve ; and that the-said (the trustee?), &c. shall convey to the commissioners for the time being appointed by virtue of the act of congress, entitled, &c. and their successors for the use of the United States for ever, all the said streets, and such of the said squares, parcels and lots, as the president shall deem proper for the use of the United States; and that as to the residue of the said lots into which the lands, &c. shall be divided, a fair arid equal division of them shall be made, and if no other mode of division-shall be agreed on by consent of the said (grantor) and the commissioners for the time being, then such residue of the said lots shall be divided, every other lot alternate, to the said (grantor), &e. and all the said lots which may in any manner be divided or assigned to the said (grantor) shall thereupon, &c. be con-: veyed by the said (trustees) to the said (grantor), his heirs and assigns; and that the said other lots shall and may be sold at such time, &e. &c. as the president of the United States for the time being shall direct; and that the said (trustees), &c. will, on the order and direction of the president, convey all the lots so sold, and ordered to be conveyed, to the respective purchasers in fee simple, &c. &c.
Provision is then made that the twenty-five pounds per acre, *284to be paid by the United States for the squares, should be paid out of the proceeds of such saleá', and the residue shall be paid to the president, as a grant of money to be applied for the purposes, and according to the act of congress.
Provision is also made for other objects, not material to be mentioned, and for. a conveyance of the trust property to such other persons as the president might thereafter direct, in.fee; “subjectto the trusts then remaining to be executed, and to the end that the same may be perfected.” in pursuance of this last provision, Beall and Gantt, the trustees, made a conveyance of the premises by an indenture, dated the 30th nf November 1796, to cértain commissioners appointed under the act of congress, subject to the trusts then remaining to be executed; arid, among other things,conveyed to the commissioners all that part of the lands, &c. which, had been laid off into squares, parcels or lots for buildings,, and now remaining so laid off in the city of Washington.
Now it is important to obsérve, that the object of the. indenture to Beall and Gantt in 1791, was to carry into full and entire effect the preliminary agreement entered into by the proprietors. There is no pretence to say that that indenture hhs not fully carried that agreement jnto effect! There is no allegation in the bill of any mistake in the draft of the indenture, or that the instrument was not precisely what the parties intended it should be. The argument at the bar has not attempted to set up any such mistake as a ground of equity. And indeed, after such a lapse of time, and acquiescence in its legal accuracy and sufficiency by all the parties; and after so many acts done under it, which have been.silently confirmed by the parties; it would be impossible to insist upon any such mistake with a chance of success. We must take the indenture, therefore, as we find it, as a complete execution of the preliminary agreement, and as expressing the true intent and definitive objécts of the parties. The preliminary agreement then became, upon the execution of the indenture, functus officio, and was merged in the more formal and solemn stipulations of the latter. It was no longer executory, but executed. The indenture itself contained many executory trusts ; and so far as any of them *285yet remain unexecuted, the instrument itself may still be denominated executory. But so far as the trusts have been fulfilled, as by the^ conveyance of lots to the grantors, or to purchasers, and especially by the conveyance of the streets and squares, &c. to the commissioners in 1796, the indenture can no longer be deemeu executory. Its functions have been final and complete.
We need not therefore inquire into the distinction taken in a court of chancery, between executory and executed agreements; or into the extent to.Which its equitable jurisdiction will be interposed to reform instruments upon grounds .of mistake, or to grant other relief r because the present bill presents no case falling under either predicament. Here we have a solemn instrument embodying the final intentions and agreements of the parties, without any allegation of mistake; and we are to construe that instrument according to the legal-import of its terms.
Now, upon such legal import, there do not seem grounds for any reasonable doubt. The streets and public squares are declared to be conveyed “for the use of the United States for ever.” These are the very words which by law are required to vest an absolute unconditional fee simple in the United States. They are the appropriate terms of art, if we may so say, to express an unlimited' use in the government. If the government were to purchase a lot of land for any general purpose, they are the very words which the conveyance would adopt, in order to grant an unlimited fee to the use of the government. There are no bther words or references in the instrument which control in any manner the natural meaning of them. There are no objects avowed on the face of it,-which imply any limitation. How then can the court defeat the legal meaning, and resort to a conjectural ¡01601“?
. It has been said, that by looking at the preliminary agreement, the court will see that terms of a more limited nature are there used. Be it so. But will that justify the court in reporting to it'to explain or limit the legal import of words in a solemn instrum§a , which contains no reference to it “? If we could resort to it, the natural conclusion would be, in the *286absence of all contrary proof, that the last instrument embodied the real intent of the parties ; that the preliminary agreement éither imperfectly expressed their intent, or was designedly modified in the final act. The general rule of law is, that all preliminary negotiations and agreements are to be deemed merged in the final, settled instruments executed by the parties; unless a clear mistake be established. In this very case, it may be true, for aught that appears, th^t( the president might have insisted upon the introduction intov the trust deed of the very words in controversy, to the use of the United States for ever, in order to avoid the ambiguity of the words of the preliminary agreement, He may have required an unlimited conveyance to the United States; so that they might be unfettered in any future arrangements for the promotion of the health, the comfort, or the prosperity of the city. But it is sufficient for us, that here there is a solemn conveyance, which purports to grant an unlimited fee in the streets and squares, to the use of the United States'; and we know of no authority which would justify us in disregarding the terms, or limiting their import, where no'mistake is setup and none is established. It would, indeed, be almost incredible that any substantive mistake should have existed, and never have been brought to the notice of the trustees, or to that of the. commissioners, upon their succeeding to th'e trust; or seriously insisted on by any party, down to the time of filing the present bill. The.presentis not a bill to reform a contract or deed ; but to assert rights supposed to grow out of the trusts declared in the deed.
This yiew of the matter renders it unnecessary for the court 'to go into an examination of the facts insisted upon in the answer to repel the allegations in the bill, or to disprove the equity which it asserts. If the United States possess, as we think they do, an unqualified fee in the streets and squares, that defeats the title of the plaintiffs, and definitively disposes of the merits of the cause.
It is the opinion of the court,• Mr Justice Baldwin dissentjpg, that the decree of the circuit court, dismissing the bill, fcfe affirmed with costs.
See acts of Maryland of the 23d of December 1788, 19th of December 1791, 23d of December 1792, and of the 28th of December 1793. Act of Virginia of the 3d of December 1789.