Union Pacific Corp. agreed to acquire Norfolk Southern Corp. in a cash-and-stock transaction valued at $85 billion, forming a transcontinental rail

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.