The world's largest operating steam locomotive made its way through the Chicago suburbs on Friday and was on display today in West Chicago. Despite the temperature and higher than normal humidity today there was quite a large crowd there to see it.
The 133-foot-long Big Boy No. 4014 is part of Union Pacific's tour to celebrate the 150th anniversary of the First Transcontinental Railroad.
Only 25 of these massive Big Boys trains were built. No. 4014, which was delivered to Union Pacific in 1941, was retired in 1961 and later restored to make trips around the country
You can track the Big Boy's route here.