Wienhold was an adherent of Sir Arthur Palmer, who served as Premier of Queensland from 1870 to 1874.

He held the seat until he resigned on 1 February 1875 as he intended to travel to Europe.

[4] With partners he acquired substantial landholdings, which in 1888 amounted to 289,996 acres (117,357 ha) in the Moreton and Darling Downs districts of Queensland.

[4] Wienholt retired in 1880 and settled in Ross on Wye in Herefordshire, England.

He travelled to Australia frequently in his retirement and he died in Melbourne on 14 January 1904.