An entrepreneur best known for his leadership of the Pennsylvania Railroad (PRR) from 1852 until his death in 1874, Thomson made it the largest business enterprise in the world and a world-class model for technological and managerial innovation.

[2] John Edgar Thomson was born in 1808 in Springfield Township, Delaware County, Pennsylvania, near Philadelphia, to a family with Quaker roots whose immigrant ancestors had arrived in the colonial era.

His father John Thomson was a leading civil engineer, who helped build the Chesapeake and Delaware Canal and the first experimental railroad in the United States.

He worked closely with his father from an early age, acquiring a sound foundation of engineering practice which he augmented by reading, observation, and experience.

Through his father's influence, he became a member of Pennsylvania state's engineer corps, surveying routes for a rail line west from Philadelphia.

He located the road, negotiated and oversaw construction contracts, operated portions as they opened, and promoted possible connections to the north and west.

He repeatedly reorganized the company into more efficient subdivisions, and to better cost accounting, paying careful attention to the selection of vice presidents.

At a cost of $7.5 million the Pennsylvania now dominated the state and took control of most short-haul traffic from the many towns along its heavily populated route.

Thomson then built up Philadelphia as a transatlantic port, creating the American Steamship Company in 1870 under the control of the Pennsylvania Railroad.

It took the lead in changing its engines to run on coal rather than wood burning, and from iron to steel (in constructing rails, bridges and cars).

Thomson developed a new kind of management suitable for a large dispersed corporation with many functions, partly based on the work of Daniel McCallum.

Thomson had a vision of a transcontinental line, invested his own money in several ventures, and briefly in 1871 the Pennsylvania controlled the Union Pacific.

[2] Alfred D. Chandler Jr., a Harvard Business School professor, stated in 1965 that the large-scale problems of management became obvious in the middle of the 19th century with the rise of the great railroad systems, such as the Pennsylvania and the Baltimore and Ohio.

New methods had to be invented for mobilizing, controlling, and apportioning capital, for operating a widely dispersed system, and for supervising thousands of specialized workmen spread over hundreds of miles.

A historic marker commemorates the location of his birth in his hometown of Springfield Township, Pennsylvania, and a street in the community is named for him.