Howell was elected as a Democrat to the Eighty-first and to the two succeeding Congresses, serving in office from January 3, 1949 to January 3, 1955. He was not a candidate for renomination in 1954, but was an unsuccessful candidate for election to the United States Senate, losing by a narrow margin to Clifford P. Case. He was appointed New Jersey State Commissioner of Banking and Insurance in February 1955, serving until March 1, 1969. He was a delegate-at-large to the 1956 Democratic National Convention.