Union Pacific is seeking to buy Norfolk Southern in a $85 billion deal that would create the first transcontinental railroad in the U.S, and potentially trigger a final wave of rail mergers across the country.

The merger would create the United States’ first coast-to-coast rail network, spanning 50,000 miles and 43 states.

OMAHA, NEB. — Union Pacific Corp. has agreed to acquire Norfolk Southern Corp. for $85 billion, a merger that would unite two of North America’s Class I freight railroads and major US-based grain shippers to create the country’s first transcontinental railroad.