American Military History, Volume 2 by Richard W. Stewart

A major overhaul of the Army's tactical organization accompanied the reorganization of the service's staff. Experience had demonstrated that the pentomic division lacked staying power and that it needed more troops to conduct sustained combat operations. The Army ad- dressed those issues in 1961 by revising its divisional structure to ensure greater flexibility and a better balance between mobility and firepower.

Under the Reorganization Objective Army Division (ROAD) con- cept it developed, the Army formed four types of divisions: infantry, armor, airborne, and mechanized. Each contained a base and three bri- gade headquarters. The base contained a headquarters company, a mili- tary police company, a reconnaissance squadron, division artillery, and a battalion each of supply and transportation, engineer, signal, medical, and maintenance troops.