Largely unschooled, barely literate, and with poor eyesight, Trenwith had a gift for oratory and public speaking which was to assist him in union organising and later as a politician.

He was instrumental in coordinating the 1884 bootmakers' strike from Melbourne Trades Hall, which saw Victoria's first fullscale picketing and was an important campaign in the fight against sweated labour.

[1] Trenwith honed his public oratory skills at North Wharf on the banks of the Yarra River, in Melbourne on Sunday afternoons, along with Joseph Symes, Chummy Fleming, and Monty Miller and many other Australian labour movement activists and radicals of the time.

[2] After a number of attempts at nomination, Trenwith was elected in May 1889 for the seat of Richmond (1889–1903) to the Victorian Legislative Assembly[3] on a labour platform and sought reforms in education, unemployment and tariff protection.

During 1892 Trenwith was elected leader of the Victorian Labour Party but continued to have problems at the grassroots with strong opposition from public meetings chaired by Chummy Fleming.

Eggleston),[7] and often wearing a silk top hat, his undeniably significant career in labour politics seems to have been a stage in a journey which left his origins far behind him.