Heco attended a Roman Catholic school in Baltimore and was baptized "Joseph" in 1854. He returned to the West Coast for further study, when in 1857 he was invited by California Senator William M. Gwin to come with him to Washington, D.C. as his secretary. Here he became the first nonofficial Japanese person to be introduced to a U.S. President. Heco stayed with Gwin until February 1858. He then joined Lt. J.M. Brooke on a survey of the coast of China and Japan. In June of that year, Heco became the first Japanese subject to become an American citizen.