Combining Union Pacific and Norfolk Southern into the first transcontinental railroad in the U.S. would create a 52,215-mile colossus that could offer seamless service from coast to coast, bypassing longtime interchange choke points in Chicago and at gateways along the Mississippi River.

Union Pacific and Norfolk Southern confirmed that they are in “advanced” merger talks that would create a single U.S railroad with service stretching from the East to the West Coast. The Associated Press reported last week that the companies were discussing a tie-up but neither company acknowledged that until Thursday morning.