He won the seat for New Jersey's 8th District's in the November 1960 election. Canfield was not a candidate for renomination in 1960, and so Joelson was pitted against Republican Walter P. Kennedy. Joelson won the election by nearly 14,000 votes, capturing a 52%-43.8% majority. He was sworn into the United States Congress on January 3, 1961. As Congressman, one of Joelson's achievements was a piece of legislation in 1969 that saved many school libraries. The legislation appropriated over a billion dollars for public school libraries, remedial programs and guidance counseling.