He was a member of the Western Australian Legislative Assembly from 1910 until 1914, representing the seats of Beverley and Pingelly.
[1][4][5] His next foray into politics was more successful, with Harper winning the seat of Beverley in the Legislative Assembly in a 1910 by-election.
[8] He served a full term and stood again at the 1914 election this time being defeated by Henry Hickmott of the Country Party, 889 votes to 657.
[1][9] Harper married Margaret Jane Thomas on 19 September 1891 at her family home in Naseby.
[1][2] On 5 September 1924 Harper married his second wife, Olive Estelle Story at Scots Church in Melbourne, Victoria.