The ancestry of President James Knox Polk is as follows: Thomas Gillespie’s (1719-1796) daughter Lydia (Aug 18, 1754-1826) married James Knox Nov 4 1772. (1752-1794) They had a daughter Jane (Nov 15, 1776-??). Jane Knox married Samuel Polk (1768-1827) on Dec 25, 1794. Their son James Knox Polk born Nov, 2, 1795 became the 11th President of the United States. This has been documented and proved to be affected by DNA analysis.