Henry Mitchell (September 16, 1830 – December 1, 1902) was an American oceanographer and hydrographer, and a co-founder of the National Geographic society. Born in Nantucket to surveyor and astronomer William Mitchell (December 20, 1791 - April 19, 1868), Henry joined the U.S. Coastal survey at the age of 19, and produced for the survey many charts of the waters near his home, both on Nantucket and Martha's Vineyard. He worked for four years to produce a chart of New York Harbor, which was hailed as the most accurate of its contemporaries. During his service with the survey he devised new methods for measuring tides and currents, advancing the science of hydrography beyond the production of new charts. He traveled extensively, visiting Europe to study the old world's canals, dykes and harbors, and even visited the Suez Canal in Egypt as it neared completion. In 1888 he would be among the thirty-three luminaries to found the National Geographic Society, proving instrumental in bridging fields in order to build the multidisciplinary foundation upon which the Society was based.