He took office one month after the ratification of the 16th Amendment of the Constitution permitted a federal income tax .
He helped pass the Revenue Act of 1913 , which reintroduced a federal income tax to lower tariff rates .
Taking office one month after the ratification of the 16th Amendment of the Constitution permitted a federal income tax , he helped pass the Revenue Act of 1913 , which reintroduced a federal income tax to lower tariff rates .