From Missouri - A Guide to the "Show Me" State - Route 1 section:
The CHURCH OF ST. FERDINAND, west end of St. Francis St., is the oldest church dedicated to the sacred Heart in the United States. The white brick building forms the center of a T-shaped group whose wings consist of the rectory and the Convent of the Sisters of Loretto. The cornerstone, which was presented to Father de la Croix by Mother Rose Philippine Duchesne, was laid by him February 19, 1821; on November 21 of the same year the church was blessed and opened for services. It was consecrated by Bishop Joseph Rosati, September 2, 1832. The present structure replaces an old log church
erected on the site about 1788. The Rectory, a two-and-a-half-story brick building with dormer windows, was built in 1819.
In 1870, an extension of some 20 feet and a new facade of late Gothic design were added to the church. The interior of the building contains the original galleries on the right and left of the altar. The one on the left used by Negro slaves, and that on the right by Mother Duchesne and the Sisters of Sacred Heart, and later the Sisters of Loretto. A white and gilt wooden tabernacle preserved in the church was made in 1789 by a local cabinetmakers for the first log building; the tabernacle in used at present, likewise white and gilt, dates from 1821... Preserved in the altar is a life-size wax figure of St. Valentine wearing his priestly vestments and holding a chalice, also brought from France by Bishop Du Bourg. The figure contains relics of the Saint.
"St. Ferdinand's parish was established in 1789 and soon became the community center. The present church was constructed in 1821 and is believed to be the oldest Catholic church in the upper Louisiana territory.
Old St. Ferdinand Shrine, with its wings, forms a group of buildings of unusual historical and architectural importance. The convent wing, built in 1819, is one of the few brick buildings in Missouri of this age and is almost in its original condition. It is considered one of the best examples in brick of the Federal style of architecture in the state. All of the buildings have been listed on the National Register of Historic Places, a cultural inventory of our nation's irreplaceable resources, and form St. Ferdinand's Shrine Historic District.
St. Rose Philippine Duchesne, one of Missouri's foremost pioneer women, canonized July 3, 1988, lived in the convent from 1819 to 1827 and again from 1834 to 1840. Here she established the first school in Florissant." ~ St. Louis Catholic Archdiocese
St. Ferdinand ceased as a parish church in 1955. Old St. Ferdinand Shrine and Historic Site is owned, preserved, maintained and protected by Friends of Old St. Ferdinand, Inc., a non-profit organization founded in 1959
The shrine is open for tours on Saturdays and Sundays from 1 pm and 4 pm.