Party affiliation: Republican
On staff New Bedford Mercury, 1861. Went to field of war, 1862, in North Carolina In 1864 entered dry goods house of White, Brown & Company, Boston, but 7 years later formed firm of Ladd & Davis (dry goods), Providence, Rhode Island, incorporated, 1887, as The H. W. Ladd Company, its successor, he being pres. Governor Rhode Island, 1889-1890, 1891-1892.
Founded Commercial Club. Vice president Providence Board of Trade 2 years. President Rhode Island Society for Prevention of Cruelty to Children.
President Rhode Island School of Design. One of organizers Providence Congressional Club. Presented fully equipped astronomical observatory, erected 1891, to Brown University.