Second United States Army was originally formed 15 October 1918 during World War I. It functioned as a training and administrative headquarters until being deactivated 15 April 1919. It operated 1933 to 1966, training and organizing troops for overseas deployment during World War II. It later operated under U.S. Army Forces Command as a regional command to control Army Reserve forces 1983 to 1995. Second Army was reactivated on 1 October 2010 as U.S. Army Cyber Command/Second Army, it is based at Fort Belvoir, Virginia.