A blue blazer is a type of cocktail create by Jerry Thomas, a bartender and author, while he was working at the El Dorado in San Francisco. Reportedly while Thomas was making the drink, President Ulysses S. Grant was so impressed that he gave Thomas a cigar. Thomas would only make the drink if the outside temperature was 50° F or below or if the person ordering the drink had a cold or the flu, whose symptoms the drink was to alleviate.