The plural form of "sergeant major" is "sergeants major."

The correct manner of address is "Sergeant Major," or "Sergeant Major Jones." (Unless, of course, her name is Smith.)

There are three ranks within the pay grade of E9 - Sergeant Major, Command Sergeant Major, and Sergeant Major of the Army. There is only one Sergeant Major of the Army.

There was no such thing as the Sergeant Major of the Marine Corps until 1957. The first Sergeant Major in the Marine Corps was Sergeant Major Archibald Sommers who became the Corps' first Sergeant Major in 1801.

The United States army consists of twelve ranks. They are, in order of rank, Private, Private First Class, Specialist, Corporal, Sergeant. Staff Sergeant, Sergeant First Class, Master Sergeant, First Sergeant, Sergeant Major, Command Sergeant Major, and Sergeant Major of the Army.