Union Pacific wants 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.

WASHINGTON (Reuters) -Union Pacific's proposed purchase of smaller rival rail operator Norfolk Southern will need to be approved by the Surface Transportation Board in Washington, an independent federal agency that oversees competition and other areas of importance in the rail industry.