Morgan was exchanged in January 1777 and placed by George Washington in command of a picked force of 500 trained riflemen, known as Morgan's Riflemen. Morgan and his men played a key role in the 1777 victory at Saratoga along the Hudson River in upstate New York, which proved to be a turning point of the entire war. Bitter after being passed over for promotion and plagued by severe attacks of sciatica, Morgan left the rebel army in 1779. A year later he was promoted to brigadier general and returned to service in the Southern Department.