American Civil War-John Alexander McClernand was an American lawyer and politician and a Union general in the American Civil War. He was a classic case of the politician-in-uniform coming into conflict with career Army officers graduates of the United States Military Academy. He was a prominent Democratic politician in IlliNois and a representative in the U.S. Congress before the war and then served as a subordinate commander under Ulysses S. Grant in the Western Theater fighting in the battles of Belmont Fort Donelson and Shiloh in 1861