When Union soldiers from the 6th Massachusetts Militia and some unarmed Pennsylvania state militia known as the "Washington Brigade" from Philadelphia with their band marched through the city at the start of the war, Confederate sympathizers attacked the troops, which led to the first bloodshed in the Civil War during the Baltimore riot of 1861. Four soldiers and twelve civilians were killed during the riot, which caused Union troops to later occupy Baltimore in May under Gen. Benjamin F. Butler of Massachusetts. Maryland came under direct federal administration—in part, to prevent the state from seceding—until the end of the war in April 1865.