Daniel Craig McCallum (1815–1878) was a railroad engineer and manager.
McCallum was born in Scotland in 1815. In 1822 his family emigrated to New York when he was still a boy. In Rochester he spend a few years at elementary school, and didn't follow his fathers footsteps to become a tailor. Instead he left school to become an accomplished carpenter and did some designing as an architect.[1]
He became the General Superintendent of the New York and Erie Railroad in 1855, then founded the McCallum Bridge Company in 1858. He was an early proponent of the organizational chart as a way to manage business operations.[2]
In February 1862, Edwin M. Stanton, the Secretary of War, appointed McCallum Military Director and Superintendent of the Union railroads. McCallum's successful organization and management of the railroads earned him a promotion to Major-General.
McCallum developed the McCallum inflexible arched truss, used in wooden railroad bridges across the US and Canada in the 19th century. The advent of steel bridges effectively made obsolete his unique design. The only remaining example in the world of the McCallum truss is the Percy Covered Bridge (1861),[3] ironically an automobile and footbridge. It crosses the Chateauguay River at Powerscourt, Québec, between the municipalities of Elgin and Hinchinbrooke.
He also wrote a set of poems,[4] the most famous of these was called 'Lights on the Bridge', which he wrote shortly before his death for his friend, Sam Campbell, who was a fellow railroad engineer, but was killed in 1842.