Kirchhoffer served as an Ensign in the Fenian raids in 1866 and subsequently was Captain of one of the Companies of the Portuguese Hope (46th) Battalion. He moved to Manitoba in 1883, and was called to the Manitoba Bar in 1884. Kirchhoffer founded the town of Souris, Manitoba and the Plum Creek settlement, and served as Reeve and Mayor of Souris.
Kirchhoffer also served on the Western Judicial District Board, representing Brandon and Dennis counties.
He was called to the Senate on December 16, 1892 on the advice of John Sparrow David Thompson representing the senatorial division of Selkirk, Manitoba. A Conservative, he was Chairman of the Senate Divorce Committee in 1895 and 1896, and of the Senate Contingent Committee in 1897.
He served 22 years until his death in 1914. Kirchhoffer was also a keen cricketer, representing Canada in a match against the United States on the Germantown Cricket Club Ground, Nicetown, Philadelphia in 1880, scoring one run and taking two catches in a drawn match.
He served as president of the Ontario Cricket Club and of the Canadian Zingari cricket club
In 1881 and 1882, Kirchhoffer captained Canadian International cricket teams which played against the United States.
He was a member of the Legislative Assembly of Manitoba from 1886 to 1888 representing Brandon West.