Born in Lock Haven, Pennsylvania, Sloan began his career as a newspaper artist in Philadelphia while studying with Thomas Anshutz at the Pennsylvania Academy of the Fine Arts. Under the influence of Robert Henri, he began painting in oils in the mid 1890s and followed the older artist to New York in 1904. There he became a member of The Eight (sometimes called the Ash Can School), participating in the 1908 Macbeth Gallery exhibition and subsequently in the 1913 Armory Show. He also enjoyed a long association with the Art Students League, as teacher and president, and worked two years as art editor of The Masses.
Encouraged by his friend and mentor Henri, Sloan motored to Santa Fe in 1919 with his wife Dolly and the Randall Daveys. There he established a summer home in 1920, returning for the next thirty-one years to paint landscapes and scenes of southwestern life. Sloan actively promoted exhibitions of American Indian art in the East, encouraged younger Santa Fe artists, and advised the fledgling art museum. His own summer work in New Mexico admitted a certain spiritual and chromatic freshness to his work.
Charles Eldredge, Julie Schimmel, and William H. Truettner Art in New Mexico, 1900–1945: Paths to Taos and Santa Fe (Washington, DC: National Museum of American Art, Smithsonian Institution, 1986)