64 Pa. Stat. § 145
Applications of actual settlers for lands lying north and west of the rivers Ohio and Allegheny and Conewango creek, under the act, entitled "An act for the sale of the vacant lands within this commonwealth," passed April 3, 1792, describing particularly the lands applied for, and filed with the secretary of the land office, vouching such other requisites as is provided for by the act of September 22, 1794, entitled "An act to prevent the receiving any more applications, or issuing any more warrants except in certain cases, for any land within this commonwealth," shall, for two years from and after the passing of this act, entitle the applicant, his heirs and assigns, to all the privileges and benefits that an original or vacating warrant would entitle them to; and on the trial of all suits brought or to be brought between warrantees and actual settlers, concerning lands situate as aforesaid, the actual settler shall be permitted to plead and make proof of his improvement and residence, as fully and with equal force and effect as if such settler had obtained a vacating warrant; but nothing in this act contained shall be construed to impair any contract or agreement, nor to bar the legal or equitable claims of any person or persons to said lands, nor to release said lands from the conditions of settlement, residence, improvement, purchase money and interest, required by the aforesaid act of April 3, 1792, nor to the granting of any lands heretofore reserved or appropriated by law.
64 P.S. § 145