July 29 (Reuters) - Union Pacific (UNP.N) , opens new tab said on Tuesday it would buy smaller rival Norfolk Southern (NSC.N) , opens new tab in an $85-billion deal to create the country's first coast-to-coast freight rail operator.

Such mergers have historically reshaped the rail map, consolidating regional carriers into some dominant networks, but often come under intense scrutiny from the Surface Transportation Board.

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Landmark mergers in the past - such as the creation of BNSF and between Union Pacific and Southern Pacific - have set the stage for today's concentrated rail network, often triggering both operational gains and regulatory pushback.

Here are some of the largest railroad deals in the past three decades:

https://www.reuters.com/sustainability/sustainable-finance-reporting/major-rail-mergers-that-reshaped-us-freight-network-2025-07-29/