The United States Marine Corps (USMC) is a branch of the United States military responsible for providing power projection from the sea, utilizing the mobility of the U.S. Navy to rapidly deliver combined-arms task forces. Alongside the U.S. Navy, the Marine Corps operates as a part of the United States Department of the Navy.

 

Originally organized as the Continental Marines on November 10, 1775 as naval infantry, the Marine Corps has evolved in its mission with changing military doctrine and American foreign policy. The Marine Corps has served in every American armed conflict including the Revolutionary War. It attained prominence in the 20th century when its theories and practice of amphibious warfare proved prescient and ultimately formed the cornerstone of the Pacific campaign of World War II. By the mid 20th century, the Marine Corps had become the dominant theorist of amphibious warfare. Its ability to rapidly respond to regional crises has made it, and continues to make it, an important body in the implementation and execution of American foreign policy.