5 Things You Didn't Know About the American Civil War 1. One-third of the soldiers who fought for the Union Army were immigrants, and nearly one in 10 was African American. 2. Black Union soldiers refused their salaries for 18 months to protest being paid lower wages than white soldiers. 3. Before William Tecumseh Sherman became a great Union general, he was demoted for apparent insanity. 4. More men died in the Civil War than any other American conflict, and two-thirds of the dead perished from disease. 5. Both before and during the Civil War, Abraham Lincoln pushed to send freed slaves abroad.