The story
"Tell it to Sweeney! (The Stuyvesants will understand.)” was an advertisement for the New York (NY) Daily News, first appearing in August 1922. The Daily News positioned itself as the newspaper of the average working man—such as the Irish “Sweeney.” The name “Stuyvesant” was used to represent blue bloods. Thus, if you advertise in the Daily News and reach the Sweeneys of New York City, the Stuyvesants will also get the message.
Etymology from Wiktionary, CC BY-SA 4.0.