 Under the Toronto Transportation Commission, the Yonge line was the busiest and most congested streetcar line in the city leading to its replacement in 1954 by the Yonge Subway line, also Toronto's first and the first in Canada.On September 10, 1861, the Yonge streetcar line became the first streetcar line in Canada.It ran from Yorkville Town Hall (north of Bloor Street at Scollard Street and Yonge Street), south on Yonge Street then east on King Street to St. Lawrence Hall.