The Jackson Square cast iron monogram AP, standing for Almonaster and Pontalba was designed by Gaston, son of the Baroness Michaela de Pontalba, daughter of don Andres Almonaster y Roxas. First of its kind in the city, the cast iron work of the Pontalba galleries was soon imitated giving to New Orleans its unique atmosphere. The Upper Pontalba (closest to Canal St.) was built in less than a year (1849-1850) at a cost of $156,000. The opposite row (Lower Pontalba) for $146,000. Michaela, the owner and developer, estimated it should be cheaper as the contractor had already gained experience.