Jacob Penner was born August 12, 1880, in or near Ekaterinoslav (today's Dnipropetrovsk), Ukraine, then part of the Russian Empire, to a German-speaking Mennonite family.

Appalled by the poverty among the peasantry in the Tsarist regime, Penner became a revolutionary socialist at an early age — political activity which forced him to emigrate to Canada in 1904.

[2] It was there that he met his future wife, Rose Shapack, a Jewish Russian immigrant, in 1906 during an address by Emma Goldman at the Winnipeg Radical Club.

Penner was active in the Canadian One Big Union movement (OBU),[3] and played a role as an organiser of the Winnipeg General Strike in 1919.

[4] With little hope of winning office in the election, Penner made use of the campaign to advocate for world revolution, not hesitating to declare his allegiance to the Communist International and appealing for the overthrow of capitalism.

The international solidarity of the proletariat is not merely a toy or a fine phrase for the workers, but a vital necessity, without which the cause of the working class is doomed to destruction.

[6] Penner would be regularly re-elected as a Winnipeg alderman, holding the position until 1960, excepting a time during WWII when he was put in a concentration camp for being a Communist.

[8] This allowed for the Minister of Justice, in this case Ernest Lapointe, to order the arrest and detention of individuals deemed dangerous to public safety as prisoners of war.

[8] Arrested together with John Naviziwsky as "active and dangerous Communists,"[9] Penner was interred in a camp for political prisoners located at Kananaskis, Alberta, outside of Calgary.

[8] Following his release, Penner joined his Communist Party associates in advocating publicly for the immediate opening of a second front in Europe to take military pressure off the Soviet Union, which was fighting for its survival in the aftermath of Nazi Germany's Operation Barbarossa.