His father managed a printing roller factory, and Hart worked there for a time in his teens but lost the job due to an explosion that took place when he was off sketching instead of watching the glue vats.

[3] For the first few years of the 20th century, Hart traveled all over the world: to Mexico, Central America, North Africa, the Caribbean, and the South Pacific, where he visited Tahiti in 1903, shortly after the death of Gauguin.

From his early travels onward, Hart worked often in the highly portable medium of watercolor, and he developed a loose, vigorous style that eventually attracted the attention of Knoedler Gallery in New York, which gave him his first show.

[2] After moving to the New York City area, Hart became part of an artist colony in Fort Lee, New Jersey, that included such champions of avant-garde art as Walt Kuhn, Arthur B. Davies, and Edward Hopper.

His style varies: some works show affinity with the delicate expressiveness of John Marin and Cézanne, while others lean towards the brusquer social realism of Diego Rivera or Robert Henri.