An underutilized resource for researchers interested in Native American records is the US Congressional Serial Set. This government publication contains over 15,000 volumes comprised of Senate and House documents and reports bound by the Session of Congress, starting in 1817 with the 15th Congress. The 38-volume American State Papers provide additional information from the 1st to the 14th Congresses.
In regards to Indian Affairs, the volumes describe the legal and fiscal relations between the US government and tribes (for example), but they are also a useful reference source for genealogical research. The largest category of American Indian documents relate to claims prosecuted against the government for losses caused by “Indian depredations” and for service in the Indian wars.
You can search the digital Serial Set when connected to the National Archives network at any of our facilities. Some libraries and universities have also purchased access to the site. http://congressional.proquest.com/