There used to be a great search for patent records available online. A lawsuit over lack of sufficiently safeguarding privacy of Native American Tribes caused all records to be pulled, but the Land Patent Search is now back up!
You can search it for yourself here: http://www.glorecords.blm.gov/PatentSearch/
While the information is transcribed, only some of the documents have an actual image available. However, you can find Charles P. Ingalls in Minnesota, Carrie C. Ingalls in South Dakota, and Peter Ingalls in Florida among others.
UPDATED January 20 2018: I double checked the link and added my current signature block.
Sarah S. Uthoff is the main force behind Trundlebed Tales striving to bring the History, Mystery, Magic and Imagination of Laura Ingalls Wilder and other greats of children’s literature and history to life for a new generation. Uthoff is a nationally known Laura Ingalls Wilder authority and has presented at five of the Wilder homesites, many conferences and numerous libraries, museums, and events around the Midwest. Attend one of her programs, schedule one yourself, watch her videos, listen to her podcast, and find her on Facebook, Twitter, Google+, LinkedIn, and Academia.edu. Professionally she is a reference librarian at Kirkwood Community College and director of the Oxford (Iowa) Public Library.