Renwick became an important leader of the Gothic revival in the U.S. Having already become a successful and widely acclaimed architect by the 1850s, St. Patrick’s Cathedral was the most significant commission of Renwick’s career. It became his greatest success, yet lack of sufficient funds forced Renwick to rework his original plans. The most significant alteration was the use of plaster as a substitute for the masonry he had originally planned for the vault. The lack of funds was a reason for the Gothic movement's decrease in  its momentum.

St. Patrick’s Cathedral was Renwick’s masterpiece. He oversaw every detail that went into the cathedral that would become one of the most important in the history of American architecture.