The Cathedral-Basilica of Saint Louis, King of France, also called St. Louis Cathedral, is the seat of the Roman Catholic Archdiocese of New Orleans and is the oldest cathedral in what would become the United States. The first church on the site was built in 1718; the third, built in 1789, was raised to cathedral rank in 1793. Enlarging the building to meet the needs of the growing congregation had been pondered since 1834, and J. N. B. de Pouilly was consulted to design plans for a new building. The cathedral was expanded and largely rebuilt in 1850, with little of the 1789 structure remaining.