The Bureau of Land Management has done a wonderful job indexing the land records, and providing over 5 million images from 1820 to present day. The site is located at http://www.glorecords.blm.gov/.
The site states the following about the land patent records.
"Federal Land Patents offer researchers a source of information on the initial transfer of land titles from the Federal government to individuals. In addition to verifying title transfer, this information will allow the researcher to associate an individual (Patentee, Assignee, Warrantee, Widow, or Heir) with a specific location (Legal Land Description) and time (Issue Date). We have a variety of Land Patents on our site, including Cash Entry, Homestead and Military Warrant patents."
Just recently I used this site to look up information on the FOX family and their movement to Ohio in the early 1800's; work that had been done by my mother through letters and trips to the county court house. Here, I was able to look up the land patent in 1820 of a cash sale to Henry FOX; Philip AIRHART; Andrew MILBOURN; Samuel CRAIG; James CRAIG; and Joseph RHODES; and George JAMES. What is amazing is that of the seven individuals listed - five are direct relatives of the FOX family. However, it does open up the question about who was Philip AIRHART AND George JAMES. Which is why genealogy research never ends.