Native Land is a searchable tool which allows you to enter an address and see which tribes, languages, and treaties are associate with that location. Also includes links to further resources, such as tribal websites and sources for additional information.
The U.S. National Archives provides information from their own collections and links to informative digital projects. This includes genealogical, historical, and contemporary sources.
Past landowners can be verified from deed research and tax records. Much of this information is a matter of public record.
United States Land and Property
Introduction to U.S. Census Records
Ancestry.com (U.S. Census Records and numerous other records)
HeritageQuest (or read this first for more information about what is included)
The path the discovering people associated with a landscape often depends on going through the individuals or institutions who held legal ownership of the land.
Prior to 1865, "Slave Schedules" were a part of the U.S. Census. Names are not give for those enslaved but this shows if a particular person (such as the person who held deed to the acres you are studying) was legally enslaving people.
Census records show where people lived and include names of those who are renting rather than owning. Pre-1865, this includes only those who were free as enslaved persons on the separate schedules. The Census is done every 10 years. Much of it was lost for 1890 and prior to 1850 it only included the name of the head of household. However, other interesting details show up depending on the particular census decade that may give you a better sense of who was there and how the landscape might have been used.
Guide to African American Genealogy and resources available through Guilford's library.