Foster was born in Cincinnati, Ohio and spent most of his childhood there apart from a three year sojourn in Colorado. In 1898 he enrolled at the Cincinnati Art Academy where he studied under Joseph Henry Sharp and Frank Duveneck. In 1902 he moved to New York where he kept the wolf from the door by painting theatrical scenery and backdrops for large department stores. Meanwhile he studied at the New York School under Robert Henri and William Merritt Chase. In 1903 he sold his first illustration to ‘Life’ Magazine and began a successful career as a graphic artist working for all the principal publications of the day including From that time, he worked for most of the major magazines including ‘Collier's’, ‘The Saturday Evening Post’ and ‘Harper's Monthly’.
During the Great War he served with the American Volunteer Motor Ambulance Corps in France and spent some time as a camouflage artist. On his return he moved to Chicago where he taught at the Art Institute. In 1926 he won the National Academy of Design's Clark Prize for the best figure composition painted in the United States by a non-academician. The following year, he was voted an Associate Member based on recognition for his painting The Girl in Brown.
After the Second War he moved to Los Angeles and devoted his energy to painting, exhibiting, and teaching. He taught at the Chouinard School of Art in Los Angeles and gave private classes in his studio. He also worked on a mural project at the Hearst estate in Wyntoon, California and was an active member of the California Art Club.