The Herbert Hoover Presidential Library houses the papers of Rose Wilder Lane

http://hoover.archives.gov/

The Frontier in American History, by Frederick Jackson Turner

http://www.gutenberg.org/files/22994/22994-h/22994-h.htm

The U.S.-Dakota War of 1862

http://usdakotawar.org/resources

Libertarian writings of Rose Wilder Lane

http://www.libertarianism.org/people/rose-wilder-lane

Mary Ingalls at the Iowa Braille and Sight Saving School

http://ibsssalumni.org/html/mary_ingalls_era_1877_-_1889.htm

Laura Ingalls Wilder Historic Home and Museum, Mansfield, Missouri

http://www.lauraingallswilderhome.com/

Beyond Little House

http://beyondlittlehouse.com/