Land patent
A land patent, also referred to as a letters patent (which can also apply to inventions), is a deed conveying property by the federal government to a landowner outside of the original 13 colonies. Originally the federal agency was the General Land Office (GLO), which was replaced by the Bureau of Land Management (BLM).
As a grant by the federal government, these patents are more often litigated in federal rather than state court.
New York
The State of New York had a Commissioners of the Land Office that issued letters patent, separate from the federal government. As many as 854 reported cases by New York courts discuss this. Only 0.8% of New York is owned by the federal government, making it one of only 5 states having less than 1% of its state owned by the federal government.[1]
Texas
About 540 reported decisions, two-thirds of them federal, discuss land patents in Texas. Due to its history as its own sovereign nation, federal ownership of land in Texas is a relatively small 1.9%, and thus federal land parents are relatively rare there.[1]