Huge 'Big Boy' train makes a rare trip East. Here's where it's going

The world's largest steam train is heading east across the Mississippi River to help celebrate America's 250th birthday.

The train, officially known as Big Boy No. 4014, is making a 10-state swing starting in late May. Delivered to Union Pacific in 1941, the locomotive was among 25 built to haul wartime freight across the Continental Divide in Wyoming and Utah. Big Boy is the last one running, and in the 1960s was converted to burn oil instead of coal.

“Union Pacific couldn’t be prouder to share this powerful piece of history with the nation and to be a part of America’s birthday celebration,” Union Pacific CEO Jim Vena said in a statement. “This tour celebrates our company’s rich 164-year history, our nation’s amazing story and the people who have helped build our great country and our railroad.”

The ground-shaking locomotive has already done a western swing through California from its home base in Cheyenne, Wyoming. It will depart again for the east on May 25. The train has only rarely ever been back east of the Mississippi River since its delivery in 1941.

Big Boy is 133 feet long and weighs 1.2 million pounds. It traveled more than 1 million miles during its working life hauling freight between Cheyenne and Ogden, Utah. The train typically draws large crowds of rail enthusiasts, and it's common to see superfans with cameras in hand chasing it in cars.

The Union Pacific railroad is closely tied to President Abraham Lincoln, who founded the railroad in 1862 during the Civil War as a way of helping link California to the rest of the United States. The 1869 completion of the transcontinental railroad transformed the movement of people across the country. Less than two decades years earlier, they largely walked the Oregon Trail to move west across the Mississippi River.

Big Boy will make the following stops, but there are other public viewing opportunities posted on the Union Pacific website. UP also provides a real-time location tracker.

• May 30 – Omaha, Nebraska (home of Union Pacific’s headquarters)
• June 3 – West Chicago, Illinois
• June 10 – Buffalo, New York
• June 15-16 – Scranton, Pennsylvania
• July 4-5 – Philadelphia, Pennsylvania
• July 9-10 – Altoona, Pennsylvania
• July 14 – Fostoria, Ohio
• July 19 – St. Louis, Missouri

(This story has been updated because an earlier version included an inaccuracy.)