Final answer:
The Progressive Era reformers aimed to reduce government corruption by including the direct election of senators in the Seventeenth Amendment, which allowed citizens to vote for senators instead of state legislatures doing so.
Step-by-step explanation:
Reformers of the Progressive Era sought to reduce corruption in government by adopting a constitutional amendment that provided for the direct election of senators. This significant reform was encompassed within the Seventeenth Amendment to the U.S. Constitution, ratified in April 1913. The amendment replaced the practice of having state legislatures elect U.S. senators, a process that was often dominated by political machines and corruption, with a system where senators would be chosen via popular vote by the citizens of each state. This change was in line with the broader Progressive objective to make government more responsive to the will of the people and to increase citizen participation in the electoral process. Several Progressive Era leaders, including William Jennings Bryan and Robert M. La Follette, were instrumental in bringing about this and other democratic reforms.