Union Pacific’s Big Boy steam locomotive draws huge crowds on rare tour

Tens of thousands gathered in Philadelphia over the Fourth of July weekend as Union Pacific’s Big Boy No. 4014 made a public display stop on its rare coast-to-coast steam tour. The 1940s-era locomotive is Union Pacific’s only operational Big Boy and the world’s largest operating steam locomotive. The eastern leg of the 2026 run stretched to more than 50 whistle-stops in 10 states and eight major display events, including first-time stops in Indiana, Ohio, New York and Pennsylvania.

Big Boy No. 4014 was delivered to Union Pacific in December 1941, when the railroad needed heavy power for the war effort. After a multi-year restoration that ended in 2019, the engine returned to the rails as part of Union Pacific’s heritage steam program, and the company has now sent it on nine tours since then. In that span, the locomotive has drawn more than 2 million people, covered more than 21,000 miles and logged 260 days on the rails.

The Philadelphia stop was timed for July 4 and July 5, with the locomotive serving as the centerpiece of the America250 Block Party. Union Pacific tied the 2026 journey to the nation’s 250th anniversary. The company also sent the train east with commemorative locomotives connected to America250 and Abraham Lincoln.

In town after town, the locomotive’s scale and rarity have turned depot grounds, museum stops and downtown streets into short-lived civic events that pull families, photographers and history buffs into the same crowd. Eight Big Boys survive, but No. 4014 is the only one in operation.

Guinness World Records lists No. 4014 as the most powerful steam locomotive currently in operation, with a tractive effort of 135,375 pound-force at 10 mph.