The original Sleeman Breweries was established in the 1850s and operated until it lost its licence due to smuggling and tax evasion, for 50 years, in 1933.

[5] John H. Sleeman was born in Cornwall, England, in 1805 and came to Upper Canada (present day Ontario) in 1834, first settling in St. David's (Niagara-on-the-Lake) where he founded the Stamford Spring Brewery in 1836.

By 1890, George Sleeman had achieved great success with Silver Creek Brewery which had sales in Ontario and Quebec.

Due to excessive investments in his Guelph Street Railway Company, he lost the businesses to the banks in 1905; he then opened the Springbank Brewery.

The Sleeman family (including younger members) subsequently worked with bootleggers to export their beer to Michigan, paying no taxes on the illegally gained profits.

Some sources (including John W. Sleeman) hint that the family was involved with Al Capone but after considerable research, historian Micheal Matchett suggests that the contact in the US was actually Rocco Perri, often called the "Al Capone of Canada" according to the book Rocco Perri: The Story of Canada's Most Notorious Bootlegger.

[6] He incorporated the new Sleeman Brewing and Malting Co. Ltd. in Guelph and began producing beer in 1988 with backing from Stroh Brewery Company for much of the $3-million he needed, a loan from a Detroit bank, and about $500,000 of his own money.

These facilities were manufacturing Sleeman, Okanagan Spring and Unibroue Canadian beers as well as the Sapporo, Old Milwaukee and Pabst Blue Ribbon brands.

Additional beers under the Upper Canada brand including Rebellion Lager, Wheat and Maple Brown Ale have since been discontinued.

Concerned this would affect the beer's taste, Sleeman compensates for this in a majority of their brews by using hops that are processed to be less light sensitive.