Who was the first American president to pay personal income tax on his presidential salary?

Question

In 1963, US President Johnson imposed a 25 % tax (almost 10 times the average) on potato starch, dextrin, brandy, and light trucks, resulting in VW vans and pickups disappearing from the U.S. market. Why?

Answer 1

Warren Harding
In 1923 Harding paid tax on his 1922/23 presidential salary, having in 1921 effectively killed a proposed bill that would make presidents permanently immune from income tax. Income tax was established in the 1913 Sixteenth Amendment.