Schwartz engaged in the newspaper business at Fort Recovery from 1892 to 1894 and at Sioux Falls, South Dakota, from 1894 to 1896.

Schwartz's political career started in the South Dakota House of Representatives, serving from 1897 to 1899, where he was elected on the Fusion ticket.

[a] He served as chief of the field division of the United States General Land Office at Spokane, Washington, and Helena, Montana, from 1897 to 1907.

Senator, Harry Schwartz played a key role in opening the door to black military pilots in World War II.

When the War Department and the Army Air Corps (AAC) did not follow through on this amendment, Schwartz made visits to General Henry H. Arnold and others to demand that black pilots be trained.