Thomson (1808–1874) was the entrepreneur who led the Pennsylvania Railroad from 1852 until his death in 1874, making it the largest business enterprise in the world and a world-class model for technological and managerial innovation.
He served as the Pennsy's first Chief Engineer and third President.
Thomson's sober, technical, methodical, and non-ideological personality had an important influence on the Pennsylvania Railroad, which in the mid-19th century was on the technical cutting edge of rail development, while nonetheless reflecting Thomson's personality in its conservatism and its steady growth while avoiding financial risks.
His Pennsylvania Railroad was in his day the largest railroad in the world, with 6,000 miles of track, and was famous for steady financial dividends, high quality construction, constantly improving equipment, technological advances (such as replacing wood fuel with coal), and innovation in management techniques for a large complex organization.

The railroad's other presidents were:
Samuel V. Merrick, (March 31, 1847—September 1, 1849)
William C. Patterson, (September 1, 1849—February 2, 1852)
J. Edgar Thomson, (February 3, 1852—May 27, 1874)
Thomas A. Scott, (June 3, 1874—June 1, 1880)
George B. Roberts, (June 1, 1880—January 30, 1897)
Frank Thomson (February 3, 1897—June 5, 1899)
Alexander J. Cassatt (June 9, 1899—December 28, 1906)
James McCrea (January 2, 1907—January 1, 1913)
Samuel Rea (January 1, 1913—October 1, 1925)
William W. Atterbury (October 1, 1925—April 24, 1935)
Martin W. Clement (April 24, 1935—June 16, 1949)
Walter S. Franklin (June 16, 1949—May 31, 1954)
James M. Symes (May 31, 1954—November 1, 1959)
Allen J. Greenough (November 1, 1959—January 31, 1968)
The Pennsylvania Railroad's board chairman/CEOs were:
Martin W. Clement (June 16, 1949—December 31, 1951)
James M. Symes (November 1, 1959—October 1, 1963)
Stuart T. Saunders (October 1, 1963—January 31, 1968)
Thomson (1808–1874) was the entrepreneur who led the Pennsylvania Railroad from 1852 until his death in 1874, making it the largest business enterprise in the world and a world-class model for technological and managerial innovation. He served as the Pennsy's first Chief Engineer and third President. Thomson's sober, technical, methodical, and non-ideological personality had an important influence on the Pennsylvania Railroad, which in the mid-19th century was on the technical cutting edge of rail development, while nonetheless reflecting Thomson's personality in its conservatism and its steady growth while avoiding financial risks. His Pennsylvania Railroad was in his day the largest railroad in the world, with 6,000 miles of track, and was famous for steady financial dividends, high quality construction, constantly improving equipment, technological advances (such as replacing wood fuel with coal), and innovation in management techniques for a large complex organization.
The railroad's other presidents were:
Samuel V. Merrick, (March 31, 1847—September 1, 1849)
William C. Patterson, (September 1, 1849—February 2, 1852)
J. Edgar Thomson, (February 3, 1852—May 27, 1874)
Thomas A. Scott, (June 3, 1874—June 1, 1880)
George B. Roberts, (June 1, 1880—January 30, 1897)
Frank Thomson (February 3, 1897—June 5, 1899)
Alexander J. Cassatt (June 9, 1899—December 28, 1906)
James McCrea (January 2, 1907—January 1, 1913)
Samuel Rea (January 1, 1913—October 1, 1925)
William W. Atterbury (October 1, 1925—April 24, 1935)
Martin W. Clement (April 24, 1935—June 16, 1949)
Walter S. Franklin (June 16, 1949—May 31, 1954)
James M. Symes (May 31, 1954—November 1, 1959)
Allen J. Greenough (November 1, 1959—January 31, 1968)
The Pennsylvania Railroad's board chairman/CEOs were:
Martin W. Clement (June 16, 1949—December 31, 1951)
James M. Symes (November 1, 1959—October 1, 1963)
Stuart T. Saunders (October 1, 1963—January 31, 1968)
Pennsylvania Railroad