The 4th Cavalry Regiment is a United States Army cavalry regiment, whose lineage is traced back to the mid-19th century. It was one of the most effective units of the Army against American Indians on the Texas frontier. Today, the regiment exists as separate squadrons within the U.S. Army. The 1st Squadron of the 4th Cavalry's official nickname is "Quarterhorse", which alludes to its 1/4 Cav designation. The 3rd Squadron of the 4th Cavalry's official nickname is "Raiders". Today, the "1st Squadron, 4th Cavalry", "2nd Squadron, 4th Cavalry", "4th Squadron, 4th Cavalry", and "6th Squadron, 4th Cavalry" are parts of the 1st Infantry Division, while the "3rd Squadron, 4th Cavalry" serves as part of the 25th Infantry Division. On 23 September 2009, the "4th Squadron, 4th Cavalry" officially stood up at Fort Riley, Kansas as part of the 1st "Devil" Brigade, 1st Infantry Division. On 28 March 2008, the "5th Squadron, 4th Cavalry" officially stood up at Fort Riley, Kansas as part of the 2nd "Dagger" Brigade, 1st Infantry Division. The 6th Squadron, 4th Cavalry served as part of the recently inactivated 1st Infantry Division, 3rd "Duke" Brigade, at Fort Knox, Kentucky.