US National Archives
Nara: Treasures of Congress: Progressive Reform: Direct Election of Senators
Check out this amazing interactive site that shows you primary documents outlining the 17th amendment proposal (click on any document) for popular election of senators, provided by the National Archives and Records Administration (NARA).
US National Archives
Nara: Treasures of Congress: Progressive Reform: Direct Election of Senators
Article briefly describing how direct election of United States senators came into being with the passage of the 17th amendment.