The Sixteenth Amendment, ratified in 1913, played a central role in building up the powerful American federal government of the twentieth century by making it possible to enact a modern, nationwide income tax. Before long, the income tax would become by far the federal government’s largest source of revenue. This Amendment was part of a wave of federal and state constitutional amendments championed by Progressives in the early twentieth century. The Amendment reversed an 1895 Supreme Court decision that had made a nationwide income tax effectively impossible by invoking what today seems an arcane distinction between “direct” and “indirect” taxes.
The Seventeenth Amendment restates the first paragraph of Article I, section 3 of the Constitution and provides for the election of senators by replacing the phrase “chosen by the Legislature thereof” with “elected by the people thereof.” In addition, it allows the governor or executive authority of each state, if authorized by that state’s legislature, to appoint a senator in the event of a vacancy, until a general election occurs.