St. Augustine’s primary purpose was to thwart the French. The breadbox papers are a collection of 19th century documents that reveal a snapshot of local history that includes slavery and shipwrecks. Over the past 450 years, St. Augustine has grown from a fledgling European settlement and military outpost ridden with violence and turmoil to Henry Flagler’s Gilded Age in the late 1800s. Built during the first Spanish Period, the Father O'Reilly House Museum is one of the oldest structures in St. Augustine -- and situated in the oldest continuously settled neighborhood. On Aviles Street south of the Ximenez-Fatio House. Philip II changed his mind, however, once French Protestants (known as Huguenots) built Fort Caroline in present-day Jacksonville. St. Augustine, oldest continuously settled city in the United States, seat (1822) of St. Johns county, northeastern Florida, about 40 miles (65 km) southeast of Jacksonville. Today, the historic city lays claim to one of Florida’s up-and-coming cultural hubs with a vibrant art and music scene. View Profile. The History of St. Augustine. It is situated on a peninsula between two saltwater rivers, the San Sebastian (west) and Matanzas (east), and on the mainland west of the San Sebastian, just inland from the Atlantic coast on the Intracoastal Waterway. Historic Downtown. See Article History. 2.