Claim: Philadelphia is the birthplace of a branch of the United States Military.

The United States Marine Corps -LRB- USMC -RRB- , also known as the United States Marines , is a branch of the United States Armed Forces responsible for providing power projection , using the mobility of the United States Navy , by Congressional mandate , to deliver rapidly , combined-arms task forces on land , at sea , and in the air . The U.S. Marine Corps is one of the four armed service branches in the U.S. Department of Defense -LRB- DoD -RRB- and one of the seven uniformed services of the United States . The current Chairman of the Joint Chiefs of Staff , the highest-ranking military officer in the U.S. Armed Forces , is a Marine Corps general .   The Marine Corps has been a component of the U.S. Department of the Navy since 30 June 1834 , working closely with naval forces for training , transportation , and logistics . The USMC operates posts on land and aboard sea-going amphibious warfare ships around the world . Additionally , several of the Marines ' tactical aviation squadrons , primarily Marine Fighter Attack squadrons , are also embedded in Navy carrier air wings and operate from the Navy 's nuclear-powered aircraft carriers .   Two battalions of Continental Marines were formed on 10 November 1775 in Philadelphia as a service branch of infantry troops capable of fighting for independence both at sea and on shore . The role of the Corps has since grown and evolved , expanding to aerial warfare and earning popular titles such as , `` America 's third air force '' , and , `` second land army '' . The U.S. Marine Corps has distinguished itself as it has served in the majority of American wars and armed conflicts , from its inception to the modern era , and attained prominence in the 20th century when its theories and practices of amphibious warfare proved prescient and ultimately formed the cornerstone of the Pacific theater of World War II .   By the mid-20th century , the U.S. Marine Corps had become a major theorist of and the world 's dominant practitioner of amphibious warfare . Its ability to rapidly respond on short notice to expeditionary crises gives it a strong role in the implementation and execution of American foreign policy . As of 2016 , the USMC has around 182,000 active duty members and some 38,500 reserve Marines . It is the smallest of the U.S. Armed Forces within the DoD .