Shiloh National Military Park was established in 1894 to preserve the scene of the first major battle in the Western theater of the Civil War. The two-day battle, April 6 and 7, 1862, involved about 65,000 Union and 44,000 Confederate troops. This battle resulted in nearly 24,000 killed, wounded, and missing. It proved to be a decisive victory for the federal forces when they advanced on and seized control of the Confederate railway system at Corinth, Mississippi, about 20 miles south. The battlefield contains about 4,000 acres. Shiloh National Military Park, Tennessee. October 21, 2003.