Nice digs, congratulations!
Here is some info on the Freedom Train.
The 1975 - 1976 American Freedom Train
The American Freedom Train (AFT) was a 26-car train led by one of three enormous steam engines restored just for the occasion. Over a 21 month period from April 1, 1975 to December 31, 1976 more than 7 million Americans visited the train during its tour of all 48 contiguous states. Tens of millions more stood trackside to see it go by. It was by far the greatest event on rails since the end of the steam era, and the uniquely magnificent vehicle that brought America's Bicentennial celebration to the people.