Daniel McCallum (21 January 1815 – 27 December 1878) was a Scottish-born American railroad engineer, general manager of the New York and Erie Railroad, and a brevet major general in the Union Army during the American Civil War. He is known as one of the early pioneers of management; in 1855, he designed an illustrative organization chart of the New York and Erie Railroad, considered to be the first modern organizational chart. It provides a plan of the organization, showing the division of administrative responsibilities and the number and class of employees engaged in each department.Photograph credit: Brady National Photographic Art Gallery; restored by Adam Cuerden