Claim: Ulysses S. Grant served under the sixteenth US president.
Evidence: As Commanding General -LRB- 1864 -- 69 -RRB- , Grant worked closely with President Abraham Lincoln to lead the Union Army to victory over the Confederacy in the American Civil War.
Abraham Lincoln -LRB- -LSB- ˈeɪbrəhæm_ˈlIŋkən -RSB- February 12 , 1809 -- April 15 , 1865 -RRB- was an American politician and lawyer who served as the 16th President of the United States from March 1861 until his assassination in April 1865.