sentences:  The lineage of the 18th Engineer Brigade can be traced to 29 July 1921, when its predecessor, the 347th Engineers (General Service), was constituted as an Organized Reserves unit.The 347th Engineers would not be activated for almost twenty years, until the military buildup after the United States entered World War II.The unit was ordered into active military service on 6 May 1942 at Camp Claiborne, Louisiana.