The Philadelphia and Reading Railroad (P&R) was one of the first railroads constructed in the United States. Along with the Little Schuylkill, a horse-drawn railroad in the Schuylkill River Valley, it formed the earliest components of what became the Reading Company. Primarily, the P&R was constructed to haul anthracite coal from the mines in northeastern Pennsylvania's Coal Region to Philadelphia.The original P&R mainline extended south from the minning town of Pottsville to Reading and then onward to Philadelphia, following the gently graded banks of the Schuylkill River for nearly all of the 93 mile jounrney. The P&R mainline had the destinction of being, upon its 1843 completion, the first double track main line in the United States .
Almost immediately the P&R became a very profitable business as coal replaced wood as fuel in businesses and homes. Soon the P&R bought or leased many of the railroads in the the Schuylkill River Valley and Pennsylvania Coal Region. The Reading also constructed Port Richmond, in Philadelphia, to load coal into ships and barges to be exported. This increased the potential market for anthracite and was key to the P&R's success. Port Richmond was the self-proclaimed "Largest privately owned railroad tidewater terminal in the world"  . In 1871, the Reading established a subsidiary called the Philadelphia and Reading Coal and Iron Company, which set about buying anthracite coal mines in the Coal Region. This vertical expansion gave the P&R almost full control of coal from mining through to market.
The Black Rock Tunnel is the second railroad tunnel built in America and the first tunnel with vertical construction shafts.