In New York, he began studying art under L. E. Wilmarth at the National Academy of Design school from 1872 until 1876.

He also studied with John George Brown and at the Art Students' League of New York when it opened in 1875.

[3] In 1876 Gaul visited the American West, and on his return began to exhibit military and western paintings at the National Academy and elsewhere.

[9] He still maintained a studio in Nashville where he worked on a series for a portfolio published in 1907 titled With the Confederate Colors.

[10] He did tackle the Great War but with little success, and he died on December 21, 1919, of tuberculosis after a long illness.