He was also Justice of the Peace for many years, he was elected Alderman of New Bedford; was Chairman of Council Committee on Education, and as such prepared a report upon which was based the order for the establishment of the free Public Library of New Bedford. On its organization, Mr. Crapo was chosen a member of the Board of Trustees. This was the first free public library in Massachusetts, if not in the world. The Boston Free Library was established, however, soon afterwards. While a resident in New Bedford, he was much interested in horticulture, and to obtain the land necessary for carrying out his ideas he drained and reclaimed several acres of rocky and swampy land adjoining his garden. Here he started a nursery, which he filled with almost every description of fruit and ornamental trees, shrubs, flowers, etc. In this he was very successful and took great pride. He was a regular contributor to the New England Horticultural journal, a position he filled as long as he lived in Massachusetts. As an indication of the wide reputation he acquired in that field of labor, it may be mentioned that after his death an affecting eulogy to his memory was pronounced by the President of the National Horticultural Society at its meeting in Philadelphia, in 1869. A fine barque built at Dartmouth, of which he was part owner, was named the "H. H. Crapo" in compliment to him.