The 5th Cavalry Regiment ("Black Knights") is a historical unit of the  that began its service on August 3, 1861, when an act of  enacted "that the two regiments of dragoons, the regiment of mounted riflemen, and the two regiments of cavalry shall hereafter be known and recognized, as the first, second, third, fourth, and fifth regiments of cavalry respectively..." and continues in modified organizational format in the U.S. Army.