He "created precise renditions of major monuments and urban spaces what are not about exotic strangeness but instead emphasize the capital's grandeur and order.
"[2] In 1841 he produced a valuable historical document in the form of a book of lithographs titled "Monumentos de Mejico, tomados del natural y litografiados por Pedro Gualdi pintor de perspectiva obsequio a los señores abonados", lithographed and published by Agustín Massé and Jean Decaen Callejon.
It was an oil painting measuring 20 by 128 feet, shown in an octagonal building designed by Gualdi himself and located at the corner of St. Charles and Poydras Streets.
Newspapers hailed the painting that showed some ten miles of surrounding countryside and depicted the buildings of the city “with wonderful accuracy.” The First Presbyterian Church of New Orleans commissioned Gualdi in 1855[5] to render a large gouache painting of Henry Howard's design for their new sanctuary which was erected facing Lafayette Square (demolished in 1938 to erect the Federal Building).
His last known work was to design a circular marble tomb for the Italian Mutual Benevolent Society in St. Louis Cemetery I in New Orleans, and he was one of the first to be entombed there after dying from malaria.