The locomotive was used for freight service on the Reading Railroad until 1957.
It was sold in 1965 to Streigel Equipment & Supply. Sold 1975 to Ross Rowland, stored many years in Hagerstown, MD roundhouse (Western Maryland Railroad), used as parts source for sister #2101.
Since its rescue in 1975, 2100 changed ownership on numerous occasions and ran infrequently in Maryland, Ohio, and later in Canada. After a fuel conversion, 2100 was transported to Tacoma, Washington where it operated in limited excursion service for a short line railroad until 2008.
No. 2100 is now transported to the B&O Roundhouse in Cleveland, Ohio in 2015 under restoration to operating condition.
As such, 2100 became the first T-1 in service.
The locomotive pulled Iron Horse Rambles excursions from 1959-1964.
On October 1962, it double-headed a passenger train with Reading No. 2102.