"Old Bald Head"; the first defense of temporary insanity; a nervous breakdown; and even our country's worst president—while many of these descriptions sound like they might be out of One Flew Over The Cuckoo's Nest, they're actually referring to some of the most bizarre individuals to come out of America's Civil War. A century-and-a-half has passed since the conflict began, when Confederates fired on Fort Sumter, South Carolina on April 12, 1861. Below is a gallery featuring some of the more unusual people involved in the war, their eccentricities at least as odd now as they were fifteen decades ago.

See more photos of the Civil War's African-American fighters, the portraits of photographer Mathew Brady, and at LIFE.com.