Lamon's Brigade was the unofficial designation for a military brigade organized for the Federal government during the American Civil War by Ward H. Lamon, the U.S. Marshall for the District of Columbia and a friend of President Lincoln. It was begun at Williamsport, Maryland, in June 1861, and continued through the end of that year. It was originally intended to be composed of Unionist Virginians, but mostly contained men from Maryland, Pennsylvania, and Illinois.