Samuel Rodger Callaway was born on December 24, 1850; the son of Frederick William Callaway of Wiltshire, England, and Margaret (Rodger) Callaway of Crieff, Scotland. His father, who was a dry-goods merchant, had lost his life and everything he owned in the Toronto fire of 1863.
The fact that he began railroad work at the early age of thirteen, as an apprentice in the auditor's office of the Grand Trunk, indicates that his formal education was meager.
From 1887 to 1895, Callaway served as president and receiver of Toledo, St. Louis and Kansas City Railroad; under his leadership the railroad was reorganized and rebuilt. It was his work at this railroad that earned the attention of the Vanderbilt family and the New York Central system.
Callaway succeeded D. W. Caldwell as president of the Nickel Plate Road in 1895. It was about this time that Callaway was also offered the position of president for the Grand Trunk system he had recently left; he declined this position based on his feeling that he would not be allowed the autonomy that he wanted from the Grand Trunk's board of directors. Callaway was succeeded as president of the Nickel Plate Road by W. H. Canniff in 1897. Callaway then succeeded D. W. Caldwell as president of the Lake Shore and Michigan Southern Railroad in 1897.
On April 20, 1898, Callaway succeeded Chauncey Depew as president of New York Central Railroad. At the time of Callaway's assumption of the presidency of New York Central, other significant leadership changes were made as well. Cornelius Vanderbilt retired from the chairmanship of the New York Central and the Michigan Central and William K. Vanderbilt retired from the chairmanship of the Lake Shore & Michigan Southern and the Nickel Plate Road, although both continued as directors for these railroads after the change.
When the American Locomotive Company (Alco) was formed through the merger of several smaller locomotive manufacturers in 1901, Callaway was selected to be the new company's first president. The merger was widely not seen as positive by the public, so the directors chose Callaway hoping his reputation as a railroad leader would help with public opinion of the company. Callaway was succeeded as president of Alco by Albert J. Pitkin.
Samuel R. Callaway died at his home in New York City on June 1, 1904, following an operation for mastoiditis.
In 1884 Callaway accepted the vice-presidency and general managership of the Union Pacific.
On June 7, 1875, he was married at Hamilton, Ontario, to Elizabeth Ecclestone.
