A month later, Sheridan commanded his first forces in combat, leading a small brigade that included his regiment. At the Battle of Booneville, Mississippi, July 1, 1862, he held back several regiments of Brig. Gen. James R. Chalmers's Confederate cavalry, deflected a large flanking attack with a noisy diversion, and reported critical intelligence about enemy dispositions. His actions so impressed the division commanders, including Brig. Gen. William S. Rosecrans, that they recommended Sheridan's promotion to brigadier general. They wrote to Halleck, "Brigadiers scarce; good ones scarce. ... The undersigned respectfully beg that you will obtain the promotion of Sheridan. He is worth his weight in gold." The promotion was approved in September, but dated effective July 1 as a reward for his actions at Booneville. It was just after Booneville that one of his fellow officers gave him the horse that he named Rienzi (after the skirmish of Rienzi, Mississippi), which he would ride throughout the war.