 The 15th Cavalry Regiment was formed in 1901 at the Presidio of San Francisco, California.Immediately upon its organization in 1901, the 15th Cavalry embarked for the Philippines to quell an insurrection in the United States' newly acquired territory.The regiment's next action was part of the Cuban Pacification from 1906 to 1909, followed by duty along the Mexican border and the hunt for Pancho Villa from December 1917 to March 1918.