For a long time 125, Dundas Street was the address of Cowan's Hardware Store. Hardware dealers tended to gravitate to the south side of Dundas between Richmond and Talbot Streets, partly because of this area's proximity to the market. Cowan's was probably the best known of London's downtown hardware stores, but other popular ones, such as Westman and Purdom (who for a long time operated from 124, Dundas), occupied shops close by for decades. Cowan's Hardware Store was founded by James Cowan, who opened his store in 1875 at 127, Dundas Street. In the 1870s London underwent a slow change that altered the physical appearance of the city and its businesses. People were also becoming aware of the gulf between the social classes. A typical late nineteenth-century mansion, which Cowan built for his family, would typically boast elegant ballrooms and parlours but also cramped tiny rooms in the "servants' quarters". As a result, there were a lot of charities in London, mostly led by churches. In general, however, the Victorian upper class continued to believe that the poor were responsible for their misfortunes, just as the rich were rewarded for their hard work and determination.

Cowan was one such Victorian champion. He climbed up the mercantile class ladder by first working for Adam Hope, one of London's first wholesalers. He later handled two businesses: a wholesale trade in carriage hardware, later substituted by auto parts, as well as a hardware business. Following a fire that erupted on January 18, 1922, the two sides of his business were separated and the wholesale operation moved to York Street. The retail department was rebuilt at the same location on Dundas, erecting the building presently standing at 125, Dundas. This structure, which exemplifies the Red or "Rug" Brick Commercial style typical of London's businesses at the time, split the old Cronyn block in two. The architectural style takes its name from the building's exterior, rug brick, which is a rough-surfaced brick that was then popular in London.

Cowan's is still remembered by many Londoners for its magnificent second-floor toy department and its fabulous Christmas displays of the much-coveted "Lionel" Electric Trains and "Meccano" steel structures.