Iowa: Slot machines debut at Dubuque Greyhound Park 25 years ago Erik Hogstrom, Telegraph Herald · November 20, 2020 at 2:16 pm Dubuque entered a new era of gaming 25 years ago. Slot machines debuted in November 1995 at Dubuque Greyhound Park. The arrival of 526 slot machines followed a referendum one year earlier in which Dubuque County voters also authorized unlimited wagers and the removal of loss limits for the Diamond Jo Casino excursion boat. Track officials had said they needed slot machines to stay in business. Here is how the Telegraph Herald reported on the debut of slot machines in its Nov. 23, 1995, edition.