He was a long-serving chairman of the District Council of Burnside, a City of Adelaide councillor, and a one-term member of the South Australian House of Assembly from 1921 to 1924, representing the multi-member seat of East Torrens for the Liberal Union and its successor the Liberal Federation.
He worked as a draper's assistant in Toowoomba and Brisbane, before moving to Adelaide, where he managed the clothing department in the Matthew Goode & Co. warehouse.
He would remain managing director of the firm, later renamed the National Clothing Manufacturing Company, until his death.
While Burnside chairman, he served one term in the House of Assembly representing the conservative Liberal Federation.
[4][5] Harper was elected as a City of Adelaide councillor in 1934, representing Hindmarsh ward; he subsequently resigned in 1938 to stand in a by-election for an alderman position, which he won unopposed.