Background
He was born in Morpeth to Denis MacMahon and Bridget Cahill.
He was born in Morpeth to Denis MacMahon and Bridget Cahill.
Educated in Maitland, he established a local store at Urala, where he was an alderman (1882–1900) and mayor (1884, 1887, 1890-1891, 1897–1900). Re-elected in 1901, he was defeated in 1904 running for Armidale. In 1907 he was the Labor candidate for Armidale.
MacMahon had moved to Sydney around 1903, and he died in 1931 in Sunderland.