[1][2] Born in 1903 in Albany, Georgia, Brosnan was the son of the town's fire chief.
[citation needed] Between 1931 and 1952, Brosnan had several promotions, from apprentice student engineer to junior engineer, division superintendent, general manager of the Central Lines of the Southern Railway and then to vice president of operations.
[citation needed] During his time as chief engineer for the Western Lines of the Southern Railway, in 1945 and 1946, Brosnan oversaw an increased mechanization of track maintenance and construction on the Southern Railway, and during his time as general manager for the Central Lines, he oversaw the automation of freight car classification in yards and terminals.
[citation needed] Bronson was notable for his impact on the railroad industry, including his implementation of labor-saving mechanical improvements, his introduction of marketing to the rail industry, his fights against government regulation, as well as his "imperious" management style.
[citation needed] Brosnan was succeeded as president by W. Graham Claytor, Jr.