Overview: The Cahokia civilization thrived in the region known today as Illinois, from 700 to 1400 AD, but when the culture mysteriously disappeared, it left behind pyramids that rivaled those of ancient Egypt. Changing with the times, Connecticut's shipbuilders shifted from sails to steam to diesel power, culminating in the construction of the first nuclear submarine. The 1859 discovery of the Comstock Lode, world's largest silver deposit, prompted the Federal government to offer statehood to Nevada, a region it had previously written off as worthless desert. Work chants, gospel and traditional folk music were combined in the Mississippi Delta to create an original American art form--the Blues. The first frontiersmen to report the wonders of Yellowstone, Wyoming, were thought to be either crazy or lying