Pennsylvania Railroad Company

Pennsylvania Railroad

PRR system map, circa 1918
Reporting mark	PRR
Locale	Delaware Illinois Indiana Kentucky Maryland Michigan New Jersey New York Ohio Pennsylvania Virginia Washington, DC West Virginia
Dates of operation	1846–1968
Successor	Penn Central Transportation Company
Track gauge	4 ft 8 1⁄2 in (1,435 mm) standard gauge
Previous gauge	at one time 4 ft 9 in (1,448 mm)
Electrification	12.5kV 25Hz AC: New York City-Washington, D.C./South Amboy; Philadelphia-Harrisburg; North Jersey Coast Line
Length	10,512 miles (16,917 kilometers)
Headquarters	Philadelphia, Pennsylvania
Website	prrths.com

The Pennsylvania Railroad (reporting mark PRR) (or Pennsylvania Railroad Company and also known the "Pennsy") was an American Class I railroad that was established in 1846 and was headquartered in Philadelphia, Pennsylvania. It was called the Pennsylvania Railroad because it was established in the state of Pennsylvania.

The PRR was the largest railroad by traffic and revenue in the U.S. for the first half of the 20th century. Over the years, it acquired, merged with or owned part of at least 800 other rail lines and companies. At the end of 1925, it operated 10,515 miles of rail line; in the 1920s, it carried nearly three times the traffic as other railroads of comparable length, such as the Union Pacific or Atchison, Topeka & Santa Fe railroads. Its only formidable rival was the New York Central (NYC), which carried around three-quarters of PRR's ton-miles.

At one time, the PRR was the largest publicly traded corporation in the world, with a budget larger than that of the U.S. government and a workforce of about 250,000 people. The corporation still holds the record for the longest continuous dividend history: it paid out annual dividends to shareholders for more than 100 consecutive years.

In 1968, PRR merged with rival NYC to form the Penn Central Transportation Company, which filed for bankruptcy within two years. The viable parts were transferred in 1976 to Conrail, which was itself broken up in 1999, with 58 percent of the system going to the Norfolk Southern Railway (NS), including nearly all of the former PRR. Amtrak received the electrified segment east of Harrisburg.

With the opening of the Erie Canal (1825) and the beginnings of the Chesapeake and Ohio Canal (1828), Philadelphia business interests became concerned that the port of Philadelphia would lose traffic. The state legislature was pressed to build a canal across Pennsylvania and thus the Main Line of Public Works was commissioned in 1826. It soon became evident that a single canal would not be practical and a series of railroads, inclined planes, and canals was proposed. The route consisting of the Philadelphia and Columbia Railroad, canals up the Susquehanna and Juniata rivers, an inclined plane railroad and tunnel across the Allegheny Mountains, and canals down the Conemaugh and Allegheny rivers to Pittsburgh on the Ohio River was completed in 1834. Because freight and passengers had to change cars several times along the route and canals froze in winter, it soon became apparent that the system was cumbersome and a better way was needed.