Harry Fenn was known as a painter, illustrator, etcher, and engraver. He began his career as a wood engraver but quickly switched to pencil drawings. He came to the U.S. in 1864 ostensibly to see Niagra Falls, but he remained for six years, then traveled to Italy to study. In 1870 he came back to the U.S. and illustrated his first book, Whittier’s Snow Bound, which was soon followed by the Ballads of New England. These were the first illustrated gift books produced in this country, and they marked an era in the history of book making. In 1870 he made an extended tour of the United States to gather material to be used for illustrations for his landmark book, Picturesque America (edited by William Cullen Bryant), a book which was published in 1872. He traveled to Europe in 1873 to make sketches for Picturesque Europe and subsequently spent two winters in the Orient for the last of the trio, Picturesque Palestine, Sinai and Egypt. The publication of these books won him fame. He returned to the U.S. in 1881 and kept a studio in New York City.
Later in life, Fenn concentrated on watercolor paintings. He was a member of the New York Watercolor Club, the Society of Illustrators, the Salmagundi Club, and was a founder of the American Watercolor Society. He exhibited at the National Academy of Design in 1864 and at various times at the Brooklyn Art Association between 1864 and 1885. He exhibited at the Columbian Expo in Chicago in 1893 where he was awarded a medal.
His White Mountain scenes include Evening in New Hampshire, Evening on Mount Washington, Mount Washington and Adams, Mount Washington under Three Feet of Snow, and Mount Washington, North Conway.