[1] McCormack was educated at a local state school and subsequently worked as a prospector in the area around Mount Morgan.

He led successful industrial action on the Etheridge railway line and oversaw a rapid increase in membership.

[1] In 1909, McCormack was elected as the full-time paid secretary of the AWA, having been blackballed by employers due to his union activities.

He led a successful strike of sugar workers in 1911, reaching a favourable settlement on wages and employment conditions.

[1] In February 1925, McCormack was defeated by William Gillies in the ballot to succeed Theodore as ALP leader and premier.