Which amendment established the direct election of U.S. Senators?

The 17th Amendment established the direct election of U.S. Senators, which significantly altered the way Senators were chosen in the United States. Prior to this amendment, Senators were selected by state legislatures, which led to concerns about corruption, political manipulation, and a lack of accountability to the public. The 17th Amendment was ratified in 1913 as part of the Progressive Era reforms aimed at increasing democratic participation and reducing corruption in the political system. By allowing voters to directly elect their Senators, the amendment aimed to make the Senate more responsive to the needs and wishes of the electorate, while promoting a more democratic government.

In contrast, the 16th Amendment relates to the federal income tax, the 18th Amendment addresses Prohibition, and the 19th Amendment grants women the right to vote, none of which pertain to the election process for U.S. Senators. This context highlights the specific focus of the 17th Amendment on enhancing democratic representation in the legislative branch of government.