The Railroad Museum of New England has been operating The Naugatuck Railroad since 1996.
The original Naugatuck Railroad opened the line in 1849, and in 1906 merged with The New York, New Haven & Hartford Railroad. On Jan 1, 1969 , Penn Central took over.
Connecticut purchased the line in 1976, and Conrail was the operator. From 1982 to 1995 Boston & Maine ran the line prior to The RMNE creating a new Naugatuck Railroad.
The RMNE/NAUG website is a well designed site that will discuss more about the railroad:
http://rmne.org/