Toronto's Rapid Transit Lines - Line 1 (Yonge-University-Spadina Subway Line)

The first Toronto subway, running under Yonge from Union Station in the south to Eglinton Station in the north, was officially opened on March 30, 1954 - https://www.toronto.ca/city-government/accountability-operations-customer-service/access-city-information-or-records/city-of-toronto-archives/whats-online/web-exhibits/canadas-first-subway/

After four years of construction, the Yonge subway — billed as Canada’s first — opens to the public. Trains shuttled through 12 stations parallel to Yonge St., between Union Station and Eglinton Ave. Passengers disembarking at these new stations could transfer from subways to streetcars or buses and back. The new subway was hailed by the TTC as a development that “puts Toronto in line with other world capitals.” - thestar.com

Photo - City of Toronto Archives/thestar.com