Leaside had its birth in railways. First was the Ontario and Quebec Railway which bought land from the Lea family (where the name Leaside comes from) during a railway mania in the 1870s. When O&QR ran into trouble, their rail line was leased (for 999 years!) to Canadian Pacific Railways which built maintenance shops and a station to service the original Union Station in Toronto. This station continued to operate until 1970 when CP discontinued passenger service.
Planning to develop the area, Canadian Northern Railway had, by 1912, bought up most of the land that now forms Leaside. They hired Fredrick Todd, an architect and town-planner from Montreal to plan the town which included the first planned industrial development park in Canada.
The Town of Leaside was incorporated in 1913. This same year saw the birth of Canadian Wire and Cable. CWC played a strong role in supporting the community through employment, a bank, and subsidizing infrastructure during its first decades.
In 1914 the Lincoln Electric Company of Canada came to Leaside, their primary business at the time was electric motors and they continue to operate here to this day.
During World War 1, CWC created the Leaside Munitions Company and produced record quantities of munitions for British and, later, U.S. governments.
In 1917 an airfield opened on 220 acres (89 hectares) of land adjacent to the Don Valley leased by the Canadian government from Canadian Wire. This was used for training air-crews during the war with men housed above the munition factory floor on Canada Wire’s property.
After the war, the airfield went into private hands as the Toronto Flying Club, the first private club aerodrome in Canada. The last hanger was removed in 1971.
1918 saw the fist “aero-mail” delivery from Toronto to Montreal starting at the Leaside Aerodrome. This was the first regular air-mail service in North America. A plaque on Broadview and Brentcliffe testifies to this accomplishment, standing on what was the northern boundary of the airfield.
In 1921 Durant Motors Inc. started a Canadian branch plant in Leaside. It became the 3rd largest domestic car manufacturer in Canada by 1924 and went on to buy its American parent company when it ran into trouble in the late 1920s. They continued to produce cars and tracks until the mid-1930s.
The next two decades saw the growth of industry as companies including TREMCO (1931), APCO Industries (1935), Nuodex Chemicals (1937), and DEL (1945) moved to Leaside. Many still have a presence in the Leaside community.
Industry grows during the war years.
World War 2 saw the birth of Research Enterprises Limited (REL) which became the single largest employer ever in Leaside. REL produced radio machinery and optical equipment for the war effort with the National Research Council. REL was sold-off in parts in 1946 as the government moved to divest itself of crown corporations.
The 1950s and beyond saw a growth in housing and community.
Many of the buildings built during the wars found a second life as schools and community centers. Leaside became part of East York in the mid-1960s. In turn, 30 years later, East York would merge with other municipalities to become the City of Toronto in 1997. Yet Leaside continues to be a vibrant community on its own merits.
Today Leaside continues to grow.
As manufacturing continues to decline across Canada, Leaside is seeing a growth in business services. Where huge factories like Canada Wire once stood, a new generation of business is being attracted by many of the same virtues that made the area attractive to their forbearers.