From Wikipedia:

Army Emergency Relief (AER), often referred to by the longer title Army Emergency Relief Fund, is a non-profit, charitable organization independent of, but closely associated with the United States Army, founded in 1942. The organization is headquartered in Arlington, VA.

An October, 1943 article in the St. Petersburg Times discusses it:

Tom Cartmell, in his July 6, 1943 letter to his father and stepmother, included an Army Emergency Relief pamphlet.