Frelinghuysen married Emily Lawrance (1911–2004), the daughter of
Charles Lawrance (the son of
Francis C. Lawrance Jr.) and Emily Margaret Gordon Dix (the daughter of Rev.
Morgan Dix, rector of
Trinity Parish). Together, they had: • Joseph S. Frelinghuysen III,
Princeton class of '63 and president of J. S. Frelinghuysen & Company, a financial advisory and private investment concern in
Mendham, N.J. • Margaret Lawrance Frelinghuysen, who married Paul Alfred Kurzman in 1964. Kurzman is a great-grandson of
Ida and
Isidor Straus, who died aboard the Titanic in 1912. Mr. Straus was a
U.S. Congressman and a co-owner of
Macy's department store. • Susan Emily Frelinghuysen, who married Robert Dudley van Roijen in 1981. van Roijen is the grandson of
Jan Herman van Roijen, the
Netherlands Minister to the
United States from 1918 to 1933. At the end of his life, Frelinghuysen was living in
Far Hills, New Jersey, and died of pneumonia on January 8, 2005, in
Morristown,
New Jersey. ==Published work==