- Union Pacific's Big Boy No. 4014, the world's largest operating steam locomotive, is touring the U.S. for America's 250th birthday celebration.
- The locomotive attracted large crowds at Valley Forge National Historical Park and Philadelphia's Navy Yard, with enthusiasts describing the experience as incredible and once-in-a-lifetime.
- Big Boy locomotives were built from 1941 to 1944 for freight hauling; only No. 4014 remains operational after restoration by Union Pacific's Heritage Operations.
- Engineer Ed Dickens operates the manually controlled, 7,000-horsepower locomotive and serves as an ambassador, emphasizing safety by urging spectators to stay 25 feet back.