Tun Tavern, a popular meeting place of 18th century Philadelphians is reputed to be the "birthplace of the Corps." Since the tavern, as well as other public meeting houses during that era, was frequented by seafaring men, it was a logical place to conduct the business of recruiting.

On Nov. 10, 1775, the Second Continental Congress passed a resolution, calling for the raising of two battalions of Marines. Samuel Nicholas was commissioned as the commanding officer. Soon after, other officers were appointed and a group of volunteers from Rhode Island arrived in Philadelphia. The Corps' first recruiting operation had begun.

Men in attractive uniforms, who were part of parades led by fifers, drummers and color guards, made their way through the streets of Philadelphia displaying their military spirit in an attempt to attract recruits. In the colonial days, and later during the Revolutionary War, Tun Tavern was known and visited by prominent citizens. Robert Mullan, whose family leased the tavern before the Revolution, as a captain of a company of Marines and a member of the Freemason's Lodge that met there. It is possible that Mullan used the tavern as a recruiting rendezvous when he raised his company in June 1776.

Tun Tavern is also associated with the birthplace of the Corps because of an account book the Mullan family used to keep business records of the tavern. That same book was used as a log to record the names of recruits who signed up in 1776. Additional information that may have helped perpetuate the legend of Tun Tavern as the birthplace of the Corps came from the Historical Society of Philadelphia. The organization had an old print of Tun Tavern, captioned "The Tun Tavern, Philadelphia. Demolished in 1900 to make way for the Merchants Warehouse," and "First two battalions of U.S. Marine Corps organized here in 1775." It is stressed, however, no documentary evidence exists to support the claim that John Adams and the Naval Committee met in Tun Tavern to draft the Nov. 10, 1775, resolution to raise two battalions of Marines, or that it was the original rendezvous for the Continental Marines.

During the early months of the Revolution, Marines served on warships. The first Continental Marine detachment recorded was aboard the sloop Enterprise on Lake Champlain. Lt. James Watson and his 17 Marines were listed on the sloop's payroll with service from May 3, 1775. The Enterprise's log is the oldest existing official record of the U.S. Marine Corps.