One great way to find out about our ancestors is land purchases & sales. I have had some very wonderful surprises pop up.
The BLM has a wonderful website that allows you to search & sometimes view original land patents www.glorecords.blm.gov/ . One drawback it is kind of hard to figure out where the lived with the land description unless you know how to read a topo map. This page will help you figure out how to read the land descriptions http://www.glorecords.blm.gov/Visitors/PLSS.asp .
My biggest complaint now would be “I don’t want to go out & buy a bunch of maps”, well http://www.esg.montana.edu/gl/trs-data.html will help with converting township & range into longitude & latitude, and link you over to terrasever so you can view a topo map & aerial photo of the land. The tough part is figuring out what meridian the land is in. The states this does cover is the 17 western state (AR, AZ, CA, CO, ID, KS, MT, ND, NE, NM, NV, OK, OR, SD, UT, WA and WY). I had one problem with an oil & gas lease, but it could have been me, a mistake on the document or the program, but it did get me in the ballpark.
Feel free to comment if you have any questions & I will expand on what I have here.