Union Pacific and Norfolk Southern are confirming they're in merger talks that would create North America’s largest railroad, stretching service from East to West Coasts.

When Union Pacific and Norfolk Southern announced their merger deal Tuesday to form “America’s first transcontinental railroad,” it puzzled some who recalled the golden spike driven in 1869 at Utah’s Promontory Summit. That last spike only connected two railroads from Omaha, Neb., to Sacramento, Calif.