First in Manila -- First in Tokyo -- First in Pyongyang. The Fifth Cavalry Regiment, raised and posted in 1855 to Fort Belknap, Texas, is the oldest unit in the 1st Cavalry Division, United States Army. Next (1866) were the Seventh and Eighth regiments. The Eighth initially saw duty at Fort Concho, Texas. On Sept. 13, 1921, the division was constituted of these and one other regiment (later dropped) at Fort Bliss, Texas, to defend the United States-Mexico border. In 1933, the Twelfth Regiment, formed in 1901 at Fort Sam Houston, San Antonio, Texas, came into the division. Dismounted in 1943 and sent to the Pacific, the division captured the Admiralty Islands, joined the invasion of Leyte, and captured Manila on order of General Douglas MacArthur to act as his "First Team" . During United Nations action in Korea, the division swept over 100 miles in 11 hours to reach Osan and win victory. It was the first force to enter the North Korean capital, Pyongyang. On July 1, 1965, at Fort Benning, Ga., it was converted to an Airmobile Division -- the first in U.S. military history. It had a distinguished record in Viet Nam. Since 1971 it has been based at Fort Hood, in the state of its creation and earliest service. (1976)