Mason began his career as an engineer working with his father at the age of 17 on a canal construction project in Albany , New York related to the Erie Canal . He subsequently attended an engineering school in Utica , New York . Mason was the first Chief Engineer of the Illinois Central Railroad . Mason and his family moved in Chicago in 1865 , when he was one of several engineers who worked to reverse the flow of the Chicago River to improve health conditions and the cleanliness of Lake Michigan . Mason held a high position with the Illinois Central Railroad until he decided to run to be Mayor of Chicago on a reform ticket in 1869 . During his administration , the Great Chicago Fire occurred . Mason responded by directing General Philip Sheridan to place the city under martial law . To date he is the last non Republican or Democratic Mayor of Chicago
Great Chicago Fire
Great Chicago Fire
Roswell B. Mason