When he was about 20 he moved to Western Australia to become a goldminer. He worked at Norseman and then at Boulder. He contracted the disease silicosis through this work.
He was secretary of the Federated Miners" Union before his election to the Western Australian Legislative Council in 1916 as a Labor member.
In 1922 he left the council, but in 1923 he was elected to the Western Australian Legislative Assembly as the member for Kalgoorlie. He was an honorary minister 1924-1927 and held the portfolios of Minister for Agriculture, Minister for Goldfields and Minister for Water Supply 1927-1930.
His alcoholism prevented him being reappointed to the Ministry in 1933 when Labor regained office. In 1936 the Labor Party decided to allow three candidates to stand for the seat of Kalgoorlie, after irregularities were discovered in the pre-selection ballotting process.
Cunningham was soundly defeated.
In 1937 he was elected to the Australian Senate as a Labor Senator for Western Australia. In 1940 he was elected Deputy Senate Leader. On 1 July 1941 he was elected President of the Senate, serving until his death in Albury, New South Wales, on 4 July 1943.
He was buried in Karrakatta Cemetery, Perth, after a state funeral.