Men who tried to catch Mosby.The Thirteenth New York horsemen were constantly held in the vicinity of Washington endeavoring to cross swords with the elusive Mosby, when he came too near, and scouting in the Virginia hills. This shows their Camp at Prospect Hill at the close of the war. During most of their service they were attached to the Twenty-second Army Corps. The Administration policy of always keeping a large army between the Confederates and Washington resulted in the turning of the National Capital into a vast military camp. Prospect Hill became the chief center of cavalry camps during the latter part of the war.