As a teenager, he clerked for the local police and left the job at age 21 after becoming involved in anarchism.

Their anarchist daily La Batalla was short-lived, starting and ending in 1910 with the Argentina Centennial's suppression of anarchism, as the pair were arrested and imprisoned in Ushuaia.

[1] Upon their release, Antillí and Pacheco founded the newspaper Alberdi and, in 1911, the short-lived journal El Manifiesto.

While Pacheco was out of the country, Antillí joined the staff of La Protesta and spent three additional years in prison for an article defending Simón Radowitzky.

Instead they created La Obra, which was originally influenced by the 1917 Russian Revolution but eventually moved away from Bolshevism and refused an "anarcho-Bolshevik" offer to launch a journal together.