Painter and printmaker George "Pop" Overbury Hart was born in Cairo, Illinois, in 1868, and his family relocated to Rochester, New York, when he was a baby. He was primarily self taught, and spent much of his spare time sketching outdoors. His father operated a printing roller factory where Hart worked for a brief time as a teenager before losing the position after he left to draw instead of watching over a glue pot, which exploded. At eighteen he left home to travel, first by cattle train to England, where he attempted to support himself as a sign painter in London; and then back to the states, where he ended up in Chicago. There, he found employment as a freelance illustrator for newspapers and a sign painter for various clients, including a gig at the 1883 Chicago World's Fair.

It wasn't until the late 1890s that Hart received his first formal art lessons, enrolling in elective classes at the Chicago Art Institute at various times. He continued to travel, including to North Africa, the Caribbean, Central America, Mexico, and the South Pacific, sketching in watercolor as he went. Of particular interest in Hart was everyday society and the activities of the working class and poor, though his subject matter also covered landscapes and cityscapes. These works eventually attracted the eye of the director of Knoedler Gallery in New York, who gave him his first solo show. In 1907 he traveled to Paris for one year to take courses at the Academie Julien, and then he returned to New York where he continued to support himself as a sign painter throughout the city, as well as a set designer for a film production company in New Jersey.

Hart soon became a oart of the an artist colony in Fort Lee, New Jersey, which included such artists as Edward Hooper and Walt Kuhn, as well as Ashcan luminaries John Sloan and Robert Henri. In the late 1910s he opened a studio in Fort Lee; however, never being one to stay in a place for long, he continued to travel, and he remained on the road for much of the 1920s. In 1921 he began working in intaglio printmaking and lithography, working from sketches he made on his travels. By the late 1920s he had developed a reputation as one of New York's leading watercolor and gouache artists, and he was included in the Museum of Modern Art's 1929 exhibition of nineteen living American painters. His work was also included in the 1932 Summer Olympic's art competition.

Ill health finally forced Hart to return to New Jersey in the early '30s, where he died in Coytesville in 1933. In 1935, the Newark Museum held a retrospective of his work in memorium. 

Hart began signing his work "Pop Hart" later in his career, having been given the nickname on his travels. Works by Hart can also be found with the signature "Hart" and "George Hart."

Hart's work is held in the collections of the Museum of Modern Art, New York; the Brooklyn Museum; the San Francisco Museum of Modern Art; the Smithsonian Institution; the Los Angeles County Museum of Art; the British Museum; and the Zimmerli Art Museum at Rutgers University, which holds some 5000 items donated by Hart's neice, Jeane Overbury Hart.