Which amendment established the direct election of senators?

The amendment that established the direct election of senators is the 17th Amendment. Ratified in 1913, this amendment shifted the election of U.S. senators from a system where they were chosen by state legislatures to a direct vote by the people. This change was intended to combat corruption and increase democratic participation in the electoral process.

Prior to the 17th Amendment, the original system allowed state legislatures to appoint senators, which often led to practices that were susceptible to bribery and political maneuvering. The push for direct elections was driven by the Progressive Era's emphasis on reforming political processes to enhance accountability and responsiveness to the electorate. The adoption of this amendment is an important milestone in U.S. history as it significantly altered the way representation is achieved at the federal level, reinforcing the principle of democracy in governance.