Mr. Justice GRIER.

This case depends upon'the solution of a single question, touching the construction of the act of Congress of 13th June, 1812, entitled “An act making further provision for settling the claims to land in the Territory of Missouri.”

This act declares “that the rights, titles, and claims to town or village lots, out-lots, common-field lots and commons, in, adjoining, and belonging to' the several towns and villages, (named in the act, and including St. Louis,) which lots have been inhabited, cultivated, or possessed prior to the 20th of December, 1803, shall be, and they cere hereby, confirmed to the inhabitants of the respective towns and villages aforesaid, according to their several right or rights in common thereto.”

It provides, also, for a survey of the out-boundary lines of the villages, so as to include the common lots and commons thereto respectfully belonging, and donates to the town, for the use of schools, all unappropriated pieces ,of land within such out-boundary.

Surveys were made of the common-fields called the Barrier de Noyer, the St. Louis common, and a’portion of the Cul de Sac field, which were claimed by the village or town of St. Louis as early as -1820, when, a township plat was returned. But no map had been constructed, which purported to' be a compliance with the.duty imposed on the Surveyor General by act, till the year 1840, when the Surveyor General constructed a map, (known in the courts-as map X,) exhibiting the out-boundary lines; but for some reason, or by mistake perhaps, the common-fields just mentioned w,ere omitted. ,

The lots claimed by the several defendants are parts of these excluded common-fields.

The .jury have found, in each case, that the lot in question *600 was a common-field lot of the villagé of St. Louis; that it was inhabited, cultivated, or possessed prior to the 20th of Uecernber, 1803, by the persons under whom the several defen 1-ants claim. •

Does the admitted fact, that these same commons are not included within the out-boundary map. X, affect the titles claimed under the act ? ,

The term common-field' is of- American invention, and adopted by Congress to designate small tracts of ground of a peculiar shape, usually from one to three arpents in front by forty in depth, used by the occupants of the French villages for the purposes of cultivation, and protected from the inroads of cattle by a common fence. The peculiar shape of the lot, its contiguity to others of similar shape, and the purposes to which it was applied, constituted it a common-field lot. It could not be confounded with lots or tracts of land of-any other character. Under the Spanish and French authorities, that species of trespassers designated by the American term “squatter ” was wholly unknown. Villagers did not venture to take possession of lots, either for cultivation or in-habitation, without a formal license from the lieutenant governor.

When.Congress, in fulfilment of our treaty obligations, came to legislate on the subject of these claims and possessions, they chose to except them from the provisions made by previous enactments,(of 1806 and 1807,) requiring proof of some concession, requéte, or survey, under the former Government, to be submitted to commissioners to have- surveys made, and a favorable report by them, before the claims were confirmed. The claims of these old villages to their common-field lots, and the peculiar customs regarding them, were well known. Congress, therefore, did not require that any documentary evidence should be filed; nor a report of commissioners thereon. A survey was considered unnecessary, because the several boundaries of each claimant of a lot, and the extent of his possession, was already marked by boundaries, well known among themselves. They required no record in the land office, to .give validity to-the title. ■ The act is certainly not drawn with' *601 much regard "to technical accuracy. It is- without that certainty, as to parties and description of the property granted, which is required in formal conveyances. But a title by statute cannot be' thus criticised. It sufficiently describés the lands intended to be granted, and the class of persons to whom it is granted. Besides, it is not.a donation, or mere gift, requiring a survey to sever it from other lands of the donor; but, rather, a deed of confirmation to those who are admitted to have just claims. It passes a present title, proprio vigore, of the property described to the persons designated; a patent to another afterwards, for any of these lands, would be void, because the Government'had already released all title and claim -thereto. If Congress could not grant them to another, much less could the arbitrary -edict, or imperfect performance of a neglected duty by a ministerial officer, operate to divest a clear title by statute.

The construction of this act of 1812 has been so often before the courts of Missouri and this court, that it would.be tedious to refer to the cases. The case of Guitard vs. Stoddard (16 How., 608) need only be cited, as it contains a review of previous decisions.

We there decide, “That the act of 1812 is a present operative grant of all the 'interest of the Hnited States in the property described in the act; and that the right of the grantee was not dependent on the factum of a survey under the Spanish Government. That the act makes no requisition for a concession, survey or permission to settle, cultivate, or possess, or for any location by public authority, as the basis of the right, title, or claim upon which, its'confirmatory provisions operate. No board was appointed to receive evidence, or authenticate titles, or adjust contradictory pretensions. All these questions were left to be decided by the judicial tribunals:”

We have.decided, also, that notwithstanding the act of 1824 makes it the duty of claimants to proceed within eighteen months to designate their lots, by proving the fact of inhabitation, and their boundaries and extent, &c., so as to enable the Surveyor General to distinguish the private from the vacant *602 lots, yet that this aet imposes no forfeiture for non-compliance.’ The confirmee, by a compliance, obtained a recognition of his boundaries; but the Government did not, by that act, impair the effect of the act of 1812.

Now, it is true that this court have not decided directly as to the effect of this map X upon the title to lots excluded by the out-boundaries there traced; but it was only because the question was not involved in the cases decided, and not from any peculiar difficulty in the question itself; for its decision is but a corollary from the principles already established by this court. If'our decision be correct, that no act of the Surveyor General was uecessary to give validity to the titles confirmed by this act, a multo fortiori, it could not operate to defeat them. • j .

The evident purpose and- object of this survey of the out-boundary,' required by the act, was to distinguish the private from, vacant lots, so that the donatiou of the remnants to the public schools might be ascertained. This duty was- neglected by the Government officers for twelve years, .when the act of 1824 was passed. At this time, the fences which surrounded these common-fields, and designated their boundaries, had rotted down, and the boundaries were difficult to ascertain. The act of 1824 was an attempt to remedy this long neglected duty of the Surveyor General. But it/'was found ineffectual; and after sixteen years more have elapsed, and the lots, whose titles were confirmed by the act of 1812, may have descended to the Second or third generations, the Surveyor Genei'al seems to have waked up to the performance of his duty. It was purely a ministerial function. His neglect could not suspend the vesting of the titles granted, much less his blunders forfeit them. If these verdicts be true, (and we must assume they are,) the Surveyor General has never yet performed the task imposed upon, him, of making a survey and map of the out-boundary,’including out-lots, eoiiimon-field lots, &c., belonging to the village, now city, of St. Louis.

The map X may be conclusive, as between the Government and the schools; but as it was not necessary, even if correct, *603 to confirm the titles under which the defendants claim, its want of correctness cannot now be a reason for their forfeiture.

Judgment of the Supreme Court of Missouri affirmed. *

Five other cases or writs of error to the Supreme Court of Missouri, all depending on the legal principle solved by this opinion of Mr. Justice Grier, were determined at the same time.