The original Commander-in-Chief's Guard, from which Company A claims nominal lineage, was authorized on March 11, 1776 and organized the next day at Cambridge, Massachusetts as the bodyguard and personal escort to Gen. George Washington.

The former "ceremonial detachment" of the Military District of Washington, a company-sized public duties unit, was reassigned to the 3rd Infantry Regiment as Company A, 4th Battalion.

[3][4] In its public duties role, the Commander-in-Chief's Guard supports general officer retirement ceremonies, state arrivals, and the presidential inauguration.

[1] It is equipped with muskets modeled on the Brown Bess (a design first developed in 1722 for service with the British Army), instead of the M14 rifle issued to the rest of the regiment for public duties.

[6][7] The CINC Guard advances a flag that is a modified version of the personal position standard of George Washington.