United States Marine Corps

The United States Marine Corps was a branch of the military of the United States of America.

In Q's first visit to the USS Enterprise (NCC-1701-D), after appearing to the crew as an Elizabethan era Captain, he then appeared as a late 20th century Marine Corps officer. Under this guise, he told Captain Jean-Luc Picard that the Enterprise had to return home to deal with the communist threat. Picard replied that nonsense was centuries behind them. (TNG episode Encounter at Farpoint).