The railroad's main route runs from the Lake Erie port of Conneaut, Ohio, to the Pittsburgh suburb of Penn Hills, Pennsylvania, a distance of 139 miles (224 km).

The original rail ancestor of the B&LE, the Shenango and Allegheny Railroad, began operation in October 1869.

[1][page needed] Rail operations were maintained continuously by various corporate descendants on the growing system that ultimately became the BLE in 1900.

The Pittsburgh, Bessemer and Lake Erie Railroad Company was founded in 1897 by Andrew Carnegie to haul iron ore and other products from the port at Conneaut, Ohio, on the Great Lakes to Carnegie Steel Company plants in Pittsburgh and the surrounding region.

In 1988 the Bessemer & Lake Erie Railroad became part of Transtar, Inc., a privately held transportation holding company with principal operations in railroad freight transportation, dock operations, Great Lakes shipping, and inland river barging that were formerly subsidiaries of USX, the holding company that owns U.S. Steel.

The Union Railroad connects at the B&LE's southern terminus at Penn Hills' North Bessemer Yard.

The B&LE constructed the shortcut K-O Line in 1901–02 to bypass the steep, winding route through Greenville.

It then passes east of downtown Greenville at a relatively high elevation, and rejoins the original line at KY, near Kremis.

Except for the Osgood Viaduct, this cut-off was double-tracked for many years but, since the arrival of CTC signaling in the 1950s, is now entirely single track.

There was originally one tunnel on the B&LE mainline at Culmerville, but it was dug out or "daylighted" in 1922, converting it to an open cut through a hill.

Bessemer and Lake Erie's locomotives, especially the SD40T-3 "Tunnel Motors," have been scattered across the CN system in the mid-late 2000s with the majority leaving the B&LE Property in March 2015.

Many of these SD40T-3s are being used on the line that feeds most of B&LE's traffic, the former Duluth, Missabe, and Iron Range Railroad in Minnesota.