Actually, I was thinking it was earlier than what reynman said. In the 1960 presidential race, the Nixon campaign alleged rampant voter fraud in Illinois, specifically the Chicago area, where they alleged that dead people voted and that many people voted twice.
They were going to contest the vote in the state, but they realized that the Kennedy campaign would then contest the vote in more Nixon-friendly states where voter fraud was also occuring

Anyways, the Daley (v1) political machine was well known for "producing" votes in the city of Chicago.