Gibbs never married, living all his life in his childhood home with his sister Julia and her husband Addison Van Name, who was the Yale librarian. Except for his customary summer vacations in the Adirondacks (at Keene Valley, New York) and later at the White Mountains (in Intervale, New Hampshire), his sojourn in Europe in 1866–69 was almost the only time that Gibbs spent outside New Haven. He joined Yale's College Church (a Congregational church) at the end of his freshman year and remained a regular attendant for the rest of his life. Gibbs generally voted for the Republican candidate in presidential elections but, like other "Mugwumps", his concern over the growing corruption associated with machine politics led him to support Grover Cleveland, a conservative Democrat, in the election of 1884. Little else is known of his religious or political views, which he mostly kept to himself.