Ouro Prêto, was a bustling place in its early days. Mines poured wealth into the region and across the sea to Portugal. Men grew rich while the boom lasted, but paid a hefty gold tax to the Portuguese crown. This imposed tax grew increasingly burdensome when the gold started petering out.
After protests ignored by the Portuguese officials, the miners revolted with the Inconfidência Mineira, but this effort was promptly crushed in 1789.