In the midst of World War II, the company was tasked with creating a more powerful steam engine that was capable of hauling heavy loads on a single locomotive, thus birthing the Big Boy.

Big Boy No. 4014 kicked off its Heartland of America Tour on Wednesday that will bring the world's largest steam engine to ...

There are steam locomotives, and then there’s “Big Boy.” At 604 tons and 132 feet long and with a 4-8-8-4-wheel arrangement, it is the largest, most powerful steam locomotive in the world.