when did the marines become their own branch
United States Marine Corps The history of the Marine Corps began when two battalions of Continental Marines were formed on 10 November 1775 in Philadelphia as a service branch of infantry troops capable of fighting on both at sea and on shore.[13] By the mid-20th century, the U.S. Marine Corps had become a major theorist of amphibious warfare, which were utilized in the Pacific theater of World War II.[14][15][16] As of 2016, the USMC has around 182,000 active duty members and some 38,500 reserve Marines.[2] It is the smallest U.S. military service within the DoD.[17][18][19]