The United States Department of Defense (DoD) consists of five branches. The Army was born first, June 14, 1775. From the DoD records (all active duty and reserve strength totals taken from their official files, dated May 31, 2017), 1,004,120 total personnel serve in the Army.
The Navy was made official Oct. 13, 1775. Some 380,741 sailors make up the strength total of this branch of service.