Elected to the United States House of Representatives in 1890, Watson pushed through legislation mandating Rural Free Delivery, called the "biggest and most expensive endeavor" ever instituted by the
Watson began to support the Farmers'
The People's Party advocated the public ownership of the railroads, steamship lines, and telephone and telegraph systems. It also supported the free and unlimited coinage of silver, the abolition of national banks, a system of graduated income tax and the direct election of
Watson rejoined the Democratic Party, and in 1920 was elected to the U.S. Senate, defeating his bitter rival Hoke Smith.
Watson died of a cerebral hemorrhage in 1922 at age 66. Rebecca L. Felton was appointed to succeed him and served (for 24 hours) as the first female U.S. Senator.