The Port Reading Railroad and its parent the Reading Railroad, as was the case for many American railroads of the time period, saw a general drop off in business as the 20th Century progressed, and the railroads fell into disrepair and eventually went bankrupt.
By the time Conrail took over most railroading in the northeastern United States in 1976, the renamed Port Reading Secondary (terminology used by Conrail to describe branch lines) was little more than a seldom used line that serviced local industries.