The exact duties vary depending on the chief of staff, though much of the SMA's time is spent traveling throughout the Army, observing training and talking with soldiers and their families.

The rank and position were based on those of the sergeant major of the Marine Corps (established in its current incarnation on 23 May 1957).

[6] The Chief of Staff of the Army created the position in 1966 after asking leaders of the major commands for a personal recommendation.

He listed seven duties and functions he expected the Sergeant Major to perform, including service as a personal adviser and assistant on matters pertaining to enlisted soldiers.

Finally chosen was the only one then serving in Vietnam, Sergeant Major William O. Wooldridge of the 1st Infantry Division.

[11] The collar insignia of the senior enlisted advisor to the chairman ("SEAC") of the JCS, approved 2 February 2006, is based directly upon that of the SMA, and features the shield of an aide de camp to the chairman of the joint chiefs of staff (without the surmounting eagle), on a gold-colored disk.