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

Union Pacific has agreed to acquire Norfolk Southern in an $85 billion deal, creating a transcontinental railroad and the largest in the U.S., the companies announced. Why it matters: The railroad megamerger requires regulatory authorization and could push other competitors BNSF and CSX into a deal of their own.

Union Pacific offers $20 billion cash and one share of its stock to buy Norfolk Southern Tuesday in a merger that could trigger the final wave of railroad mergers across the country