[3] While in Italy, DuBourg stayed at Monte Citorio, the mother church of the Congregation of the Mission order in Rome, and eventually convinced the Vincentians to send a contingent to Missouri to construct a seminary.

These two groups of priests and brothers under Felix De Andreis (1877-1820) and Joseph Rosati (1789-1843) left for the United States in the fall of 1815.

When DuBourg obtained the land grant of 640 acres from the Maryland Catholic immigrants of Perry County, they left to establish St. Mary's of the Barrens seminary in October 1818.

[5] Father Charles de la Croix was skilled in architecture and drew up the plans for both the Church and Seminary.

[6] Notable alumni included John L. Tiernon, a career United States Army officer who retired as a brigadier general.

[12] Monte Citorio in Rome is of the Tuscan Renaissance style, and this became the general model for St. Mary's of the Barrens church.

[5] It was the first non-cathedral church consecrated west of the Mississippi River and was built from stone quarried on the Barrens property.

Apparently, work on the site was then stalled for several years, because the original plans were deemed to be too elaborate and too expensive to complete.

[12] The front of the church was expanded through the addition of two side altars and a vestibule, extending the length by 40 feet.

Later additions include the Miraculous Medal Shrine in 1930, and the current Angelus bell tower which was constructed in 1980.

[14] The Sacristy of Bishop Rosati is an old log cabin that is now the oldest original structure on the St. Mary's campus.

In a move to preserve the cabin, it was set on a concrete foundation in 1932 and placed under a large arched stone pavilion to protect it from the elements.

[12][15] The Grotto of Our Lady of the Miraculous Medal was built during World War I by the seminarians on the site of the stone quarry used to construct St. Mary's Church.

[16] In August 2004, the Midwest Province of the Congregation of the Mission decided to demolish several of the old seminary buildings for the construction of a new residence for retired Vincentians.

[4][17][18] Media related to St. Mary's of the Barrens Catholic Church (Perryville, Missouri) at Wikimedia Commons