A Democrat originally from Laurel Springs, North Carolina, he was the Dean of the United States House of Representatives for his last few months in Congress.

By 1900 he owned over 5,000 acres (20 km2) of land in his native Alleghany County, North Carolina, where he raised herds of prized Hereford and Holstein cows.

His interest in farming led to his being named to the North Carolina Board of Agriculture in 1903; this marked the beginning of his career in politics.

Before being elected to Congress, Doughton served one term in the North Carolina Senate (1908–09) and was director of the state Prison Board (1909–11).

Doughton was for 18 years (1933–1947 and 1949–1953) the Chairman of the powerful U.S. House Committee on Ways and Means, and as such he co-sponsored, held hearings on, and oversaw the passage of the Social Security Act in 1935.