Letterkenny Army Depot Letterkenny Army Depot , the Center of Industrial and Technical Excellence ( CITE ) for Air Defense and Tactical Missile Systems , was established in 1942 . The depot is under the command structure of the U . S . Army Aviation and Missile Command ( AMCOM ) . The facilities at Letterkenny are used to conduct maintenance , modification , storage , and demilitarization operations on tactical missiles and ammunition . Located primarily in Letterkenny Township and extending into Greene Township and Hamilton Township , all in Franklin County , Pennsylvania , just northwest of the borough of Chambersburg , Letterkenny Depot consists of nearly 18 , 000 acres ( 71 km² ) . Letterkenny is the largest employer in Franklin County , PA , and adds over one - quarter of a billion dollars annually to the region ' s economy . Letterkenny has unique tactical missile repair capabilities repairing a variety of Defense Department missile systems , including the MIM - 104 PATRIOT missile and its ground support and radar equipment . Most recently , Letterkenny has expanded its product line to include designation of the CITE for Power Generation for the Army , the overhaul of tactical wheeled vehicles ( HMMWVs ) , material handling equipment ( 7 . 5 - ton cranes ) , and Mobile Kitchen Trailers . In 2007 during the IRAQ conflict Letterkenny began building new Mine Resistant Ambush Protected ( MRAP ) armored vehicles in partnership with BAE Systems and in 2010 was designated the Joint Depot Source of Repair ( JDSOR ) for Route Clearance Vehicles for the Depratment of Defense . History of Letterkenny Army Depot . In 1941 , Letterkenny was chosen by the U . S . Department of War to be one of twelve new ordnance depots . On December 18 , 1941 , the Secretary of War , Henry L . Stimson , issued the directive to acquire 21 , 000 acres ( 85 km² ) at Letterkenny for a depot . Letterkenny ’ s mission would be to reduce the surplus of forthcoming material and to store and ship ammunition , trucks , parts , and other supplies . In 1942 , the government obtained the James Finley House for use as the Commanding Officer ' s Residence . The first shipment of ammunition arrived by train on September 23 , 1942 . More than 3 million tons of supplies were moved during World War II . Letterkenny was one of the largest depots of its kind and was called the Springboard of Invasion in 1944 . After World War II , an enormous amount of ammunition was being returned from overseas , some of which was unserviceable and had to be destroyed . At the time of the Korean War , July 1950 , Letterkenny Ordnance Depot was in good condition to meet the emergency . The 1950s were a time of growth , as new technologies in electronics and guided missile maintenance increased the depot ' s workload . Employees were trained in these fields and began working on Project Nike missile components in 1953 . Letterkenny became a pilot depot for the implementation of the Depot Command Management System and SPEEDEX ( System - wide Project for Electronic Equipment at Depots Extended ) . In 1955 , Major Item Supply Management Agency ( MISMA ) , which provided control functions on a worldwide basis , became a tenant of Letterkenny . It evolved into the U . S . Army Depot System Command , Letterkenny ’ s immediate higher headquarters . Letterkenny became a permanent military installation on July 1 , 1954 . The ordnance depot was renamed Letterkenny Army Depot in August 1962 , and command and control of the depot fell under the U . S . Army Materiel Command . In the 1960s , with the war in Vietnam , Letterkenny ’ s missions increased . In the 1970s , command of Savanna Army Depot Activity , Illinois , fell under Letterkenny . An ammunition washout facility was built and the Northeast Area Flight Detachment moved to Letterkenny . The U . S . Army Depot System Command was established in 1976 and headquartered at Letterkenny . This 2 - star command remained at Letterkenny until 1995 , when it became the Industrial Operations Command at Rock Island , Illinois — today ’ s Operations System Command . The 1980s and early 1990s saw the depot evolving into its present form . New facilities and modernization projects , such as the Automatic Storage and Retrieval System - Plus , were constructed . Paladin ( M109 howitzer ) , PATRIOT , and HAWK work made Letterkenny a Center for Technical Excellence . In 2002 , Letterkenny celebrated 60 years of supporting soldiers and the U . S . Army .