From 1859 to 1861, Creighton served on Kingston City Council as Councillor for Victoria Ward. He became Alderman for that Ward in 1862. In 1863, he was elected Mayor of Kingston and was returned by acclamation in 1864 & 1865. During his time as Mayor, he enlarged City Park, improved sanitary conditions in the city and restored the Market wing of City Hall after the tragic fire of 1865. He also procured the clock for the dome of city hall.

In 1866, Creighton became Police Magistrate and in October of 1870, was induced to accept the position of Warden by Sir John A. Macdonald and Sir Alexander Campbell. A single parent of five children, he was not interested in raising his family in the penitentiary apartments within the compound, which he described as requiring extensive repair. As a result, Prime Minister Sir John A. Macdonald, then also Minister of Justice, approved the construction of ‘Cedarhedge’ as the official Warden’s residence of Kingston Penitentiary.

During the 1870s the Penitentiary Service was expanding with the establishment of new penitentiaries in Quebec, Manitoba and British Columbia. Newly appointed wardens of those institutions met with Warden Creighton in Cedarhedge to discuss the operation and management of their new facilities.

Considered by many to be the first true humanitarian to hold the position, Warden Creighton improved the lighting, heating and ventilation of the prison; provided better shoes, uniforms and bedding and a more varied diet to the inmates. Exercise periods were increased and extended to all prisoners. He began a lending library, night classes and improved school equipment. He introduced prison entertainment by and for inmates on holidays and visited the inmates in their cells, in the workshops, on the farm and in the quarries. In fact, he even ate his meals in the inmate Dining Hall. In 1873, when 119 inmates boarded the Steamer Watertown at the penitentiary wharf for their transfer to the new St. Vincent de Paul Penitentiary in Laval, Quebec, many of them made it known that they did not want to leave his humane custody.

Warden Creighton died on January 31, 1885 in Cedarhedge. The Daily British Whig of February 2, 1885 reported “The streets surrounding the warden’s residence [were] blocked with sleighs, and nearly every prominent citizen was in attendance. The City Police force was drawn up at the door as a guard of honour the cortege was a very long one”.