Nathaniel Craley was born in Red Lion, Pennsylvania. He graduated from the Taft School in Watertown, Connecticut, in 1946 and from Gettysburg College in 1950. He was engaged in furniture manufacturing from 1950 to 1965. He was treasurer of the York County Planning Commission from 1959 to 1965. He was the director and first vice president of York County Council of Community Services, 1960-1964, and director of York County Council for Human Relations, 1960-1963. He became chairman of the York County Democratic committee from 1962 to 1964. He was an instructor in economics and history at York Junior College from 1958 to 1959.
He was elected in 1964 as a Democrat to the 89th United States Congress. He was an unsuccessful candidate for reelection in 1966. After his term in office, he served in a number of positions in the Pacific Island territories of the United States:
He died in Glen Rock, Pennsylvania, aged 78, of undisclosed causes.