delivered the opinion of the Court:

This is an appeal by the' United States from a decree of the superior court of the eastern district of Florida, confirming a land claim.

It appears that Zephaniah Kingsley, on the 20th of November,1 18lfe, being then .an inhabitant of the province of Florida, petitioned-Go.Vernor Coppinger, stating, “ that wishing to erect a water sawmill in that creek of the river' St. John,-balled M‘Girt’s, on a vacant place, and it being necessary for that purpose to have a quantity of *480 timber sufficient to supply said mill and.establishment, he supplicate)» your excellency to-be pleased to favour-him. with your superior permission to build - the sarde on the place aforesaid, with its area of five miles square of land-as the equivalent thereof,-for' its continued' supply of timber: - bounded south-east and south by lands.granted to Ferguson and Doctor Lake;; south-west and west by yacant lands; nor.th by Don-Juan, McIntosh’s land, and east'by lands of said Kingsley, and the river'-St. John.”

Upon this, petition.the governor made-the following decree-:

.“Considering the advantage and utility which is to aceruelo {he ■province, if that is effected which Don Zephaniah. Kingsley proposes tov do,- it is 'hereby granted to him, that without prejudice of a third party, he may build a water-mill on that creek of the river St. John, called M‘Girt’s;-under the precise, condition however, that until he builds said iñ'ill,this grant will be'considered null-and void': and when the event takes place, then, in order .that .he may1 not suffer by the expensive preparations he is'making, he will- have the. facility of using the pines, comprehended within the square qf-five miles, which he solicits for the supply of said saw-mill; and no other person will, have a right to take any thing from it. Let the córrespondnding certificate be issued to hirq from the secretary’s office. .

“St. Augustine,.2d Dec. 1816.” “COPPINGER.

Upon -this decree,-the -petitioner states, that soon after'the date, of it, hé' entered upon and took, possession of the-land granted in the situation- mentioned-in said grant, and was preparing to build a water saw-mil^ agreeably to the;-condition of- the grant; but was deterred therefrom by the .disturbed.state of that part of the province of East. Florida, and the occupancy of the land by some of the tribes of Florida Indians, who were then wandering in all directions oyer the, country. : The appellee then insists that his right to the land is embraced by the treaty, between Spain' and the United States;-gives a .narrative of his submission qf his claim to1 the.hoard of commissioners, under the act. of, congress,, entitled “ an • act amending,and •supplementary to an act for ascertaining claims and'titles to land; in the,territory'of Florida, and to provide for the survey-and disposal of the public lands in Florida,” passed 3d March, 1823; that the commissioners reported, unfavourably upon it, which' he insists was contrary to the law and evidence- produced in the cause: and further, that' the report qf the commissioners upon his claim was not final, as the tract of land claimed by him, contains a larger,quantity than the *481 commissioners were authorized to decide iipon by any of the acts of congress.

• Thé petition of the appellee, of which an abstract has been just given, wás.filed on the 21st April,' 1829. : In' the .following month, the United States, by the United States’ attorney, filed an answer to this petition, denying, for sundry causes and, reasons, the entire. existence and equity of the appellee’s .claim: and in August of the eñsuing year, the United States’ attorney amended his answer, referring to certain orders of 'governor .Coppinger, dated the 27th October, 1818, and on-the 19th January, 1819: the, first of .which limits the tipie tcsix months from the 27th October, 1818, within which all grants and concessions'of land which had been made on. condition for mechanical worksj. to wit, factories, . saw-mills,' &c., were to revert to the class of public lands,, and to be declared vacant; unless the grantees, or concessioners, should comply with the conditions of such, grants or .concessions; and the second of which' declares ,.all such conditional grants or concessions null and. of no effeet, in those cases where thq persons in; whose favour they were'made, had remained inactive,' having done nothing to advance the establishment of those works. See White’s Compilation, 250, 253, 256‘, 257, for these orders. ■

The United States’ attorney alleges the appellee to be one of those persons whose supposed concession was null and void under the first order; and that it.was entirely annulled and set aside by the last, as hte had not then, nor had npt since established or advanced, ip any manner, the building of his mill, but had wholly failed and neglected to-dp so. To this answer, the appellee put in a'general replication; and the eause Came, by regular continuance, to the term of the court .in Novéinber, 1832, when permission was given to the appellee to amend his petition.. In July, 1833, he filed the amendment, stating that the disturbed and dapgeróus. condition of the. province west of the St. John’s river, which continued 'from 1812 to the exchange Pf flags, had induced Governor Coppinger to declare, by a verbal order, and decree, that the unsettled'and disturbed state of the proyince, and'the'impossibility.of the grantees of mill-grants to comply with the 'conditions of the same, with safety to themselves and their ■property,, that the grantees should hot, by a failure to erect their mills, fprfeit their titles.

Of the existence, however, of, any such modification of .the con *482 -dition of such grants, by any verbal order and decree, the appellee gave no proof on the. trial of this cause.

■ In the amendment of the appellee’s petition, the .United States’ counsel replies, denying the-existence of any such verbal order and decree by Governor Coppinger; and stating, that' if there was any ’ such danger from the disturbed condition of the province, as the appellee had alleged, that it existed as well at the time when he applied for the grant,'and when he accepted the same, as at any time .afterwards. In this state of the pleadings, the cause was brought to trial,'as well upon the evidence on the part of the. United States, as upon the part of. the appellee,; but was not then decided. At the-July term of 1885, the appellee filed, by permission of the .court, another amendment to his petition, in which, after reciting the surveys made under the decrees oí the governor upon his petition, he further says, that soon after the; grant was-made to him„he took possession of the land, and actually began to build a water saw-mill on M‘Girt’s creek, pursuant to the condition of the-grant; but that he was deterred and preventéd from completing' the same by the disturbed and dangerous state of the country, which continued until the • cession of Florida by Spain to the United States. And after that cession, he states he was deterred1 from proceeding, to the further ■ performance of the conditions of said ‘grant, by the great, uncertainty' in which,his right and title to said land was involved by said cession. To this amendment of the petition the United States’ attorney replied, repeating the facts and objections to .th.c claim of the appellee made in his previous answers; and further insisting that tne surveys, upon which the. appellee r.elied, were .made after the 24th of January, 1818, and are not agreeable to the calls of the. said supposed- grant: and that they are null and void by the provision of the latter' clause of the 8th'article of the treaty between Spain and the United States, of the 22d February, 1819.

Upon these pleadings and the evidence, the' court has decreed the appellee s claim to be Valid; thai it is,in accordance with the laws, and customs of Spain; and under and by virtue of the late treaty with Spain; and under and by virtue of the laws of nations, and of the United States.

We think differently from.the. court upon.all the.grounds stated in the decreé. They open a wide subject of remark; but we ate' stain from discussing any of them, .except the application, of the treatv to this claim, or of the laws and customs of Spain. These points we shall ouch very briefly. We first. observe, that -no *483 case of a land, claim fii .Florida, confirmed by this Court under the treaty, either in terms, or by necessary inference from what the Court has said, covers this case. We view this claim under the decree of Governor Coppinger, as a permission to enter upon the land designated in the petition and decree, in which land the appellee did not and could nbt acquire property, or even inchoate title; such as embraced in the 8th article' of the treaty,, or by this Court’s construction of it, until he had, in good' faith, prepared to- execute the condition which,the appellee held out as the inducement to obtain a grant: .or in other words, we think the decree of, the governor contains a condition precedent, to be performed by the appellee before the grant could take effect. In this case the appellee never attempted to perform the- condition: there is no proof of' his having done so'in good faith, by the expenditure of money or application of labour. On the contrary, there are, in the original petition of the appellee to the courtbélow, and,in all the subsequent amendments of -it, from, 1829 to 1833, his declarations that he had not done so, until the. amend-, merit made in 1835; when he states, for the first time', that he actually began to build á water saw-mill, according to the conditions of thp grant a short time after it wasi-made, but that-he was prevented ' from- completing it by the disturbed and dangerous condition of the country. .

. The only proof given by him of his having actually began to build, is very, equivocal, and should have been rejected by the court,' on the ground of its being hearsay; except so much of.it as relates to the remains of some work or ni'ill-dam, which of “itself could not be evidence, until, by other proof, -the appellee had established the fact of such work having been done by himself, as the witness testifying,- says expressly that it was .only from hearsay that he had said that' work was done by the appellee. The witness says, he does not know of his own knowledge that the appellee ever made any attempt,or preparations for building a saw-mill on said mill seat tract, but that he had- seen, timber on the said tract; • was told it was got by Kingsley for the purpose of building a saw-mill; that he afterwards saw a dam had been erected on each side of the stream, in the bottom of the stream saw timbers laid, as witness supposed, for the sills •of a-saw-mill; that he only knows from hearsay, that said preparations were made by Kingsley; that a part of the préparations are still remaining, and to be seen on said tract; that he first saw the timber abovementioned, in- the year 1817 or 1818, and shortly afteTsaw *484 the dam and sills aforesaid; that theLsai’d,timber;was mostly destroyed by fire. And by the record we are, left to conclude that these works were made by Kingsley, without any, even probable praóf that, he had. at anytime taken possession of' the land. We cannot do so; and-if We could¡, it would be deemed by us no compliance with the condition contained in the governor’s .decree or concession in his favour, as the1 work Was discontinued. for an insufficient cause,.that ■was, the disturbed and.dangerous-condition of the country. All.the witnesses concur .in'stating there was" no more'danger after-.the ap- - pélleé ^petitioned for the land, than there had been' before and at the tibie of his application. The appellee ,thén cannot be permitted to urge as .an,-excuse, in fact or in law, for not complying with his undertaking, a danger-which applies as forcibly to repudiate, the sincerity o.f his intention,to build a mil] when he petitioned for land for that purpose, as it does to his .inability from siich, dapger to execute it afterwards. Under- the treaty, it- is true, that grants of land made before the 24th January, 1818; by his 'catholic majesty,.or by his lawful authorities, stand. ratified and confirmed, to thq same extent, that the same grants.'woul'd be valid, if Florida, had remained undér the dominion of Spain; and the owners' of conditional grants, who have been prevented, by the circumstances .of the,- Spanish nation, from fulfilling all the conditions of their grapts; have time by the treaty extended to them to complete such conditions. That time, it was determined by this Court, in Arredondo’s case; 6 Peters; 748, 749; began to r.un, in regard, to individual rights, from the ratification of the treaty; and the treaty declares, if the conditions are not complied'with within the terms limited in the grants, that the grants shall be. null and void. It is admitted, that in the construction of .this, article -of the treaty the United States succeeds to all those equitable obligations which we áre-to suppose would have influenced his catholic majesty to secure to his subjects their property;-and which would have' been applied by him in the' -construction of a conditional’g'rant to make it absolute. And' further, in the construction of this article of. the treaty, it must be'conceded that the United States must maintain' the rights of property under it, by applying the laws and customs by ■which those rights were secured before • Florida was ceded or by which an inchoate right of property would, by laws and customs, have been adjudicated by Spanish authority, to. have -become a perfect right; by applying; in the first instance, in such cases, as was said in Arredondo’s case, the principles of justice *485 according to the rules of equity; and in the second, all those laws and customs decisive of a right of property, whilst the party claiming the right was a subject of Spain. Test then the case before us by the most .liberal equity, and it will appear that the claim' of the appellee cannot be sustained by any effort by him to perform the condition of the governor’s grant; either before the ratification óf the. treaty, or since. ' Indeed, in the last amendment of his petition, in 1835, he states he was prevented from proceeding to the further performance of the condition of said grant, by the great uncertainty in which his tight'and title to the land was involved by the cession.

These Florida grants, or concessions of land upon condition, have been repeatedly confirmed by this Court;' and it will apply the principles of its adjudications to all cases of a like kind. It will, as it has done, liberally construe a performance of conditions precedent or subsequent, in such grants. It has not, nor will it apply in the construction- of such conditions in such cases, the rules of the' common law. But this Court cannot say a condition wholly unperformed, without strong proof of sufficient cause to prevent it, does not defeat all right of property in land, under such a decree as the appellee in this case makes the foundation of his claim.

Arredondo’s grant, confirmed by this Court, 6 Peters, .was a clear case of a grant in fee for past services and commendable loyalty to his sovereign, with a condition subsequent, of a nature the performance of which must have be.en a matter of indifference as well to the king of Spain as to the United States, after a cession of Florida was made. The-condition was, that the grantees should establish on. the land two hundred Spanish families, and that they were to begin to carry into effect the establishment within three years from the date of the grant: and there was no time limited-for its completion. This Court said, in that case, 6 Peters, 745: ^ From the evidence returned with the record, we are abundantly' satisfied that the establishment was commenced within the time required, ^which appears to Jiave been extended for one year beyond that limited in the grant;) and in a manner which, considering the state of that country, as appears by the evidence, we must consider as a performance of that part of the condition.”

The case of Segui, 10 Peters, .306, was a grant in consideration of services to the Spanish government, and for erecting machinery for the purpose of sawing timber. That grant was confirmed by this Court,, upon the ground that the governor considered the services. *486 of Seguí .a sufficient consideration, and' made the ,grant absolute." Seton’s case, 9 Peters, 311, Was a decrée or permission of the governor, In.all-particulars - like that now before us;, and Seton’s .right, to. the survey which has been madé, and to the equivalent quantity to make up the extent 'of the' original concession, was confirmed' by this Court; upon'the'positive proof that Seton had built his mill ih a -yeár after the-date of the decree upon which he claimed.. Sibbald’s case, 9 Peters, 313, another like Seton’s and that before'the Court, Were-confirmed.by this Court, upon the ground tbat-Sibbald had performed tile'condition according to the rules of equity.which govern these-'cases. Sibhald,.in good faith, and.within a reasonable time .after the decree in his favour, began.to build his mill; expended five thousand dollars towards it; had his horses and negroes-stolen while the mill was building; his mill-dam carried away by a freshet-, in the absence of his millwright, who was in pursuit of the stolen.property; rebuilt his mill in 1837,, which.'was.destroyed by fire the Same year; and the yéar after, built again another mill of twenty-horse powef, ■which colxld saw twenty thousand feet.of lumber a. day.

It remains only for. us to say a word concerning the l^ws and cus^ -toms of Spain, supposed- by the learned, judge in the court' below, applicable to the confirmation of this claim under the treaty. The , fact that-no instance is known of-land so decreed having reverted to the class 'of public lands, for the non-performance of the condition* does riot prove a custom; unless a current of cases can be shown in which claimants have' held the land without performance.- Besides,' the existence of, any such'custom is.'disproved' by the decree for the'' land itself; by the--subsequent decrees of the Spanish governor, de-. daring la'nds-granted Upon condition would be null’ and void within a certain time, if the ■ conditions were .not performed; and by'the treaty itself, which stipulaten-for the performance of conditions with-.' in terms after -the treaty was made, contained in' the grants; arid', which is, recognised by this Coürt ,by its decision, that the time given only begins to rün agdnst' individual rights, from the date of-the ’ratification.,' As to the laws of Spáin, supposed to-aid the case; We-remark,-it being conbeded.tha'tAhe governor’ had authority ta make grants and concessions, and to give permission to persons to enter upon land's .upon cpnditions;' nothing less than a law dispensing with the performance of, them, or .’a release of the performance of them by the governor* sanctioned by the general royal authority under/which he'acted; ór a release by royal authority, after grants were made ge *487 neral in its application, or applicable to sorrie particular case or class of cases, can be admitted, proprio vigore, as a release of the obligations upon grantees to perform the conditions of these-grants. ^ It is not pretended that any such-law or release exists.

This cause came on to be heard on the transcript of the record -from the. superior court for the eastern district of Florida; and was argued by counsel. ■ On consideration whereof, it is the .opinion of this Court, that the -petitioner having failed to fulfil the condition of the grarit, that the said grant of concession-is null and .void; apd that the said petitioner has no right or title'to the land'. Whereupon, it is now here decreed and ordered by this Court, that the.decree of-the said superior court in this causé be,-and the same is hereby reversed and annulled; and that-this causé be, and'the sa'me is .hereby .remanded to the said superior court, with .directions to enter a decree in conformity to the opinion of this Court.