 Air defense units within the Continental United States (CONUS) were given to the Eastern and Western Air Defense Liaison Groups, with Western and Eastern Air Defense Forces activated on 1 September 1949.The command was originally assigned the region within the Continental United States (CONUS) to the east of the 102d degree of longitude, along the Canada–US border to the most easternmost point of Maine; the southern boundary being the 102d degree of longitude along the Rio Grande boundary with Mexico, east to the southernmost point of Texas and along the Gulf of Mexico and Atlantic Ocean coastlines.This was adjusted in 1951 with the activation of Central Air Defense Force (CADF) with the region being adjusted to the area east of the 90th degree of longitude south to the point of the Missouri, Kentucky and Tennessee state boundaries, and eastward to the Atlantic Ocean coastline along the Tennessee/Kentucky and Virginia/North Carolina border, with all areas north and east of those boundaries.