The son of a German-born lithographer, Henry Mosler grew up in the Midwest, spending time in Ohio, Tennessee, and Indiana. His principal instructor was Cincinnati artist James H. Beard (1859-61), but he had received earlier encouragement from George Kerr, an amateur, and had studied wood engraving in Richmond, Indiana. During the two years preceding his departure for Europe in 1863, Mosler worked for Harper's Weekly as a Civil War correspondent in the western states. He then left for Düsseldorf, where he became a pupil of Heinrich Mücke and Albert Kindler. Two years later, he moved to Paris to work under Ernest Hébert.
By 1866, Mosler had returned to Cincinnati where he executed portraits despite his distaste for that line of work. Soon after his marriage in 1869, he traveled briefly to New York but did not leave Cincinnati permanently until 1874, when he departed for three years of additional study in Munich with Alexander von Wagner and Karl von Piloty. For the next seventeen years, Mosler lived in Paris; in his painting he made a specialty in Breton peasant scenes. In 1879, his Le Retour was purchased by the French government for its Luxembourg Gallery; this is believed to be the first American painting so honored.
Mosler maintained ties with the New York art world, organizing an exhibition of 150 of his works in the galleries of the National Academy in 1885. The following year, he traveled to New Mexico with Charles T. Webber to study the Apache tribe. It was not until 1894, however, that he opened a studio in New York. Thereafter, he divided his time between visiting France and teaching in New York and Margaretville, NY. He received the Academy's Clarke Prize in 1896. Ten years following his election to Associate membership, he resigned from the Academy.
