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.

Union Pacific and Norfolk Southern today announced an $85 billion deal to tie their networks together and create the first U.S. transcontinental railroad. The merged company — which will be called Union Pacific — will transform the U.