Immediately after its organization, 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 revolutionary leader Pancho Villa from December 1917 to March 1918.

The regiment was sent in October 1919 to quell coal miners' strikes in Sheridan, Rock Springs, and Thermopolis, Wyoming.

The 15th Cavalry typically conducted inactive training period meetings at the 110th Engineer Regiment armory at 3620 Main Street or the Organized Reserve Center building at 20th and Vine Streets in Kansas City, and summer training with the 2nd Cavalry Regiment at Fort Riley, Kansas, from 1930 to 1940.

[1] With the outbreak of the Second World War, the 15th was ordered into active service on 22 March 1942 at Fort Riley, this time as a fully-mechanized unit with armored cars and tanks.

The end of the war found the 15th deep inside Germany, covering over 1,000 miles of enemy held territory since landing on the Continent in July 1944.

The 15th Cavalry Regiment met this criterion and, in March 1987, was reactivated at Fort Knox, Kentucky, by the activation of its 5th Squadron (Sabers).

Both Squadrons, as part of the 194th Armored Brigade, are charged with the mission of training the U.S. Army's enlisted Cavalry Scouts.