Columbia. Its customer base involves support to more than 350,000 RC Soldiers. First Army's mission centers around the three core functions of training and readiness: support, mobilization of RC forces and homeland defense. First Army enhances the combat readiness of RC Soldiers and units by providing training and readiness support. It facilitates the RC units' ability to execute missions throughout the full spectrum of military operations. This is done by providing observer/controller trainers and maintaining direct contact with RC units. First Army plans, prepares and executes the mobilization and deployment of RC units to provide combat-ready forces to war fighting combatant commanders. It supports presidential reserve call-ups (such as Bosnia, Kosovo and Kuwait) as well as full and partial mobilizations (such as support of homeland defense (HLD)). In fulfilling this responsibility, First Army has mobilized more than 110,000 Army National Guard and Army Reserve troops for Operations Enduring Freedom, Noble Eagle and Iraqi Freedom since the September 11 attacks in 2001. First Army conducts HLD in support of national objectives, as directed. This means First Army is the regional DoD planning agent for military support to civil authorities during a response to natural or manmade disasters. This mission directly supports the Federal Response Plan during disaster relief operations. Normally led by the Emergency Preparedness and Response Directorate and the Federal Emergency Management Agency and joined by 27 federal agencies, including the American Red Cross, First Army Soldiers and civilian employees are proud of their mission to assist American families during times of crisis. The size of the First Army (and military) response depends upon the magnitude of the event requiring military support. First U.S Army also performs two missions that, while not core functions, are significant in their importance to the Army: management of the Civilian Aides to the Secretary of the Army program and support to the National Boy Scout Jamboree. First Army serves as the higher headquarters for three reserve divisions (training support (TS)): the 85th Division (TS), headquartered in Arlington Heights, Illinois; the 78th Division (TS), headquartered in Edison, New Jersey; and the 87th Division (TS), headquartered in Birmingham, Alabama. The two important missions of training and readiness support and mobilization of RC Soldiers are accomplished through these three divisions. First Army was formed in France on Aug. 10, 1918, with Gen. John J. Pershing commanding. As America's first numbered Army, First Army engaged in two major