He was a mentor to a younger generation of American artists, who developed the style of Abstract Expressionism in the New York area.

In the 1940s and 1950s, Graham developed a new figurative style derived from classical masters, which he first showed in paintings and drawings of Russian soldiers.

[3] He went on to serve as a cavalry officer under Czar Nicholas II during World War I in the Circassian Regiment of the Russian Imperial Army.

[1] After the execution of Czar Nicholas II and his family in 1918 by the Bolsheviks during the Russian Revolution, Dombrovsky was briefly imprisoned due to his noble class.

[1] Still under the name Dombrovsky (also spelled Dabrowsky),[4] John began to study painting for the first time at the Art Students League of New York.

Patricia Thompson Graham later gave numerous works by his father to the Museum of Modern Art in New York.

[9] He was greatly interested in developing knowledge of advances and changes in the art world, and kept in touch with what was taking place in Europe as well as the US.

That year Graham met American Constance Wellman in Paris; they married in New York City in 1936 and lived in Brooklyn Heights.

[15] Wellman initiated subsequent divorce proceedings, on the grounds of "extreme cruelty, mental in nature" committed by Graham.

[17] Graham served as a mentor to younger artists such as Jackson Pollock, Willem de Kooning, and Arshile Gorky.

[18] He was also considered influential to Lee Krasner (Pollock's wife and an artist in her own right), David Smith, Dorothy Dehner, and Mark Rothko.

He showed them with work by well-established European artists: Pablo Picasso, Henri Matisse, Georges Braque, Pierre Bonnard, and Amedeo Modigliani.

[20][21] During this period and into the 1950s, Graham also continued to paint, developing a "unique figurative style" derived from classical forms; he was especially influenced by the works of Raphael, Leonardo da Vinci, Nicolas Poussin, and Jean-Auguste-Dominique Ingres.

Among his first works in this style were paintings and drawings of Russian soldiers completed about 1943, drawn from his own experience in the imperial army during World War I.