Born in Philipsburg, Quebec, Lower Canada, Eaton was a student of the National Academy of Design, New York, studying with Samuel Colman, Daniel Huntington and others.

[1] In 1872, he moved to Paris and studied at the École des Beaux-Arts under Jean-Léon Gérôme.

[2] During this time, he made the acquaintance of Jean-François Millet at Barbizon,[3] and was also influenced by his friend Jules Bastien-Lepage[2][1] to believe that his art should focus on rural life.

After his return to the United States in 1876, he painted a series of portraits of American poets for the Century magazine which were engraved by Timothy Cole (Eaton`s portrait of him is in the collection of the Art Gallery of Ontario).

[1] He became a teacher in the Cooper Institute, and opened a studio in New York City but returned to Montreal often to paint portraits.