On March 13, 1854, a second railroad, the Auburn and Port Clinton Railroad, was chartered for the project. This would connect the D&S at Auburn with the Allentown RR at Port Clinton, running parallel to the Reading main line along the Schuylkill River. The combined railroads were sometimes unofficially referred to as the Auburn and Allentown Railroad. On April 13, 1854, the charters of both the Allentown and the A&PC railroads were amended to allow them to merge with the Lehigh Valley Railroad, then building down through Allentown towards Easton (across the river from Phillipsburg). The line from Pine Grove to Rausch Gap was completed in June, and the D&S ran its first through train.