He received his academic training in the public high school of that city. His early leaning toward art was encouraged by his father, under whom the boy studied drawing and engraving until he entered the classes in the Pennsylvania Academy of the Fine Arts in 1867. He went abroad in 1868 to continue his study at the Ecole Nationale Superieure des Beaux Arts in Paris and under Leon Bonnat, and remained in Europe for eight years.
In 1864 he produced a plate titled "Young America Crushing Rebellion and Sedition, " and in 1866, "Little Samuel, " a plate after a painting by James Sant. Although well on the road to success as an etcher of portraits and mezzotints, young Sartain turned definitely to painting at the age of twenty-four and worked for a year under Christian Schussele. He sketched in Spain, England, Holland, Belgium, Germany, and Italy, spending several winters in Seville and Rome, and the year 1874 in Algiers. He collected a valuable note-book of material from which, in later years, he could develop landscapes and figure compositions. While in Italy and Algiers he painted such subjects as "View in the Street in Algiers, " "Arab Cemetery, " "Tombs of the Saints at Bouzareah, " and made studies of Italian types. It was in 1874 that he completed his "Narcissus, " a canvas now owned by Smith College, Northampton, Massachussets. His first success came when he exhibited some of his work in London in 1875 and was "hung on the line, " an honor infrequently bestowed upon foreigners. This recognition encouraged him to make his debut in an exhibition at the National Academy of Design in New York City in 1876. With his reputation already established, he returned to the United States the next year and settled in New York. Using the sketch material from his European note-book, he produced "Nubian Scheik" in 1879-80, and "A Chapter of the Koran" in 1883. In 1879 he began a parallel career as teacher when he was put in charge of all the life classes of the Art Students' League at Cooper Union. He also taught for some years at the Philadelphia School of Design for Women of which his father was vice-president and his sister Emily Sartain was principal. By 1880 he was well established in New York. In 1884 he held a special exhibition of his own at the Williams and Everett's gallery in that city, being warmly received by the critics. In 1910 he sent some of his work to the international exposition at Buenos Aires, winning a silver medal and the honor of purchase by the Argentine government. His "Nubian Scheik" was also purchased by the French government for its collection in the Luxembourg. Sartain is further represented in various public and private collections in the United States, including that of the Corcoran Gallery in Washington, D. C. , and the Metropolitan Museum in New York City. Thirty years before his death actually occurred, it was reported that he had died. One of the leading art dealers on Fifth Avenue gave credence to the rumor and enhanced the value of Sartain's pictures by trying to corner the market. Sartain, however, was quietly painting in a New England village.
He was never married.