In the 1908 case of Dupree v. Mansur, the United States Supreme Court dealt with a dispute over land ownership in Louisiana. The plaintiff, Dupree, claimed that he was entitled to certain lands under a Spanish grant made before Louisiana became part of the U.S., while defendant Mansur argued that his title came from subsequent American grants. The court ruled in favor of Mansur on two grounds: firstly because it found no evidence to support Dupree's claim that he had inherited rights from an original Spanish grantee; and secondly because even if such rights existed they would have been extinguished by prescription (a legal principle similar to statute of limitations) due to non-use for more than ten years after Louisiana's admission into the Union in 1812. Therefore, any later American grants were valid and conferred good title upon their recipients including Mansur.

In the dissenting opinion for Dupree v. Mansur, Justice Harlan argued that the majority's decision was a departure from established principles of law and equity. He contended that when an individual purchases property with full knowledge of existing liens or encumbrances on it, they should not be allowed to subsequently claim those liens are invalid due to technical errors in their recording. In this case, he believed Mr. Dupree knowingly purchased land subject to a mortgage held by Mr. Mansur and therefore had no right later to contest its validity based on minor discrepancies in record-keeping procedures at the county level where the property was located.