Final answer:
The Seventeenth Amendment provided for the direct election of U.S. senators.
Step-by-step explanation:
The Seventeenth Amendment to the U.S. Constitution, which was added with the help of the progressive movement, provided for the direct election of U.S. senators. Prior to this amendment, senators were chosen by state legislatures. However, the Seventeenth Amendment mandated that senators be elected by the people, similar to how representatives are elected to the House of Representatives.