The depot was built in 1870 to service the Boston and Maine Railroad and was the former terminus of the line before its extension to Haverhill. The MBTA purchased the Haverhill Line in 1973, intending to replace commuter rail service with extended Orange Line subway service between Oak Grove and Reading. This plan was rejected by riders who desired to retain commuter rail service. The second track was not rebuilt through the station when the outbound platform was built, so the inbound platform serves trains in both directions. Despite this limited capacity, Reading is the terminus for some local trains on the line.