Final answer:
There have been 16 Sergeant Majors of the Army, a prestigious position that represents the top enlisted rank and serves as the senior enlisted advisor to the Army Chief of Staff.
Step-by-step explanation:
As of the time of my knowledge cutoff in early 2023, there have been 16 Sergeant Majors of the Army (SMA), including the current one. The position of SMA is the highest enlisted rank within the U.S. Army and serves as the senior enlisted advisor to the Army Chief of Staff. Those who hold this prestigious position are responsible for addressing issues regarding the enlisted force, and often serve as a bridge between the highest-ranking officials and the enlisted soldiers.