At Maurice "Red" O'Donnell's three-story house in Homewood, the phone rang constantly with calls from customers. Between the 1930s and 1950s, he painted signs for such clients as Dad's Root Beer, Meadow Gold Ice Cream and Borden's Milk all over Pittsburgh. The son of Irish immigrants belonged to a fraternity of brush-wielding, overalls-wearing men called "wall dogs" who created an idiosyncratic form of commercial art that promoted beer, bread, cigars, flour, well-tailored clothes, soda pop and any other product or service someone wanted to sell. Many of these large signs are still visible in Pittsburgh and other Midwestern and mid-Atlantic cities partly because they were often applied to brick walls with lead-based paint.