The Mississippi Marine Brigade was a Union Army amphibious unit which included the United States Ram Fleet and operated from November 1862 to August 1864 during the American Civil War. The brigade was established to act swiftly against Confederate forces operating near the Mississippi River and its tributaries. The brigade was commanded by Brigadier General Alfred W. Ellet and operated in coordination with the Mississippi River Squadron during the Union brown-water navy battle against the Confederate River Defense Fleet and land based forces. The brigade was independent of the Union Army and Navy and reported directly to the Secretary of War, Edwin M. Stanton. Despite the name, it was never part of the United States Marine Corps.