Mrs. Wagner's Pies were single-serving pies sold in waxed paper. They were made until July 11, 1969, by a company named Mrs. Wagner's Home Made Pies that was originally located in Ocean Grove, New Jersey, and later in Brooklyn, New York.
In September 1940, The Newark News described F.W. Birkenihauer as president of Mrs. Wagner's Pies, the "largest pie bakery in the country, with its home plant in Newark and five branches as far west as Chicago." Nonetheless, the company went out of business in July, 1968.
The pies are mentioned in "America", a 1968 song by Simon and Garfunkel.
References
Mrs. Wagner's Pies Wikipedia(Text) CC BY-SA