On Monday, October 25th, 1841
Lincoln purchases from his father and mother 40-acre tract in Coles County for $200. Thomas Lincoln purchased this tract December 31, 1840, from his stepson John D. Johnston for $50. Thomas Lincoln and wife are to have use of land during their lifetime. Indenture: Thomas and Sarah Lincoln to Abraham Lincoln, 25 October 1841, CW, 1:262-63.

Related sources from The Collected Works of Abraham Lincoln

Bond

Acknowledgment of Deed

Indenture: Thomas and Sarah Lincoln to Abraham Lincoln

Lincoln Timemap for 1841