agreed to Dubourg's request and he and the two priests set out on horseback for St. Louis, a distance of over three hundred miles. En route, they were joined by Donatien Olivier at Kaskaskia, where they crossed the Mississippi River to reach the former French colony of Ste. Genevieve. There they were welcomed by Henry Pratte, a native of the town and the first native-born Catholic priest of Missouri. Leaving De Andreis to help in the parish there, the group continued on to St. Louis, where they were shocked to find the church and rectory, built 40 years earlier, to be falling apart, totally unfurnished and not even having doors or windows. The priests had to sleep on the ground, as there was no floor, wrapped in buffalo robes. Pratte was able to tidy up and fix the rectory to a minimal standard of occupancy, just in time for the arrival of Dubourg and his entourage on 15 January 1815. Wearing their full pontifical vestments, he and Flaget processed through the town, greeted by the majority of the 2,500 occupants of the town, and proceeded to the church, where he addressed his flock for the first time. St. Mary's of the Barrens The Catholic population of Perryville, Missouri was in need of a permanent resident priest, and had offered 640 acres of land to Dubourg in exchange for the regular services of a priest and a school for the children. Rosati moved to Perryville, where he opened St. Mary of the Barrens Seminary in 1818, to educate the young men of the region and to train new members for the Vincentian Society. For several years, he planned and supervised the construction of the school, while at the same time teaching most of the classes and functioning as the local pastor. In 1820, he was appointed the Vincentian Provincial Superior in the United States. Episcopacy In 1822, Rosati was appointed vicar apostolic of Mississippi and Alabama, and, the following year, appointed coadjutor bishop to Dubourg, whose territory extended from Louisiana to Florida. He was based in St. Louis, while Dubourg lived in New Orleans. This arrangement lasted until 1826, when, in the course of a trip to Rome, Dubourg unexpectedly submitted his resignation to the Holy See. Rosati wrote, "I was absolutely bewildered and could not persuade myself it was true." At that point, the Vatican decided to divide the diocese,