Gifford worked for the architectural firm of McKim, Meade & White for about three years, before establishing his own firm in Newark.John William Leonard, ed., Men and Things: A Biographical Dictionary of Contemporaries, Volume 1 (New York City: L. R. Hamersly & Company, 1908), p. 978. He became a member of the Architectural League of New York in 1881, and an associate of the American Institute of Architects in 1901. By 1889, he had opened an office at 50 Broadway, Manhattan.Catalogue of the Fifth Annual Exhibition of the Architectural League of New York (New York: Architectural League of New York, 1889), p. 34. He formed a partnership with William A. Bates in 1900,James Ward and Dennis Steadman Francis, Architects in Practice, New York City, 1900–1940 (J & D Associates, 1989), p. 28. an architect who had made a reputation designing houses in Bronxville, New York.Loretta Hoagland, Bronxville's Turn-of-the-Century Art Colony (Lawrence Park Hilltop Association, 1992), pp. 195–197. In 1903, the offices of Gifford & Bates were located at 18 East 17th Street, Manhattan.Florence N. Levy, ed., American Art Annual, Volume 4 (American Art Annual Inc., 1903), p. 110.
