Answer:
Seventeenth Amendment
Step-by-step explanation:
According to Article I, Section 3 of the Constitution, senators had to be elected by state legislatures, but due to the increasing corruption and inefficiency in the legislative elections, Congress saw necessary to modify the law and create a new Amendment that supersedes that article. The Seventeenth Amendment (1913) was created with such purpose. Under this new Amendment, citizens were allowed to elect senators to Congress.
The law also modifies the procedure for filling vacancies in the Senate, stating that the state executive should fill the vacancies by making temporary appointments to serve until new elections are held.