Joseph Rosati, C.M. (12 January 1789 - 25 September 1843), vowed in 1808 and ordained as a priest of the Congregation of the Mission on 10 February 1811.
In 1816 Fr Rosati sailed to the United States with Father Felix de Andreis for the purpose of starting a seminary in the See of the newly appointed bishop of Louisiana and Florida, Louis W.V. DuBourg. From 1817-1818 Fr Rosati served as a professor of theology at St. Thomas Seminary in Nelson County, Kentucky. In 1818 at Perryville, Missouri he established the school which was incorporated in 1822 as St. Mary's Seminary. He taught oversaw construction of the buildings, taught most of the classes, and also served as local pastor.
After the death of Fr de Andreis in 1820, Fr Rosati was appointed superior of the Congregation of the Mission in the United States. On 13 August 1822, he was appointed vicar apostolic of Mississippi and Alabama. On 22 June 1823 he was appointed coadjutor to Bishop DuBourg; he was consecrated bishop by Bishop DuBourg in Donaldsonville, Louisiana the next year on 25 March.
After Bishop DuBourg's unexpected return to his native France and his resignation from the episcopate, on 18 July 1826 Fr. Rosati was appointed apostolic administrator of Saint Louis, Missouri and secondarily appointed apostolic administrator of New Orleans. On 20 March 1827 he was appointed bishop of Saint Louis; his secondary appointment as apostolic administrator of New Orleans ended 4 August 1829 with the appointment of Leo Raymond de Neckère, C.M. as bishop of New Orleans. He had asked not to be appointed bishop of New Orleans because he lacked fluency in French; speaking English suited him better for ministry in the western United States. On 24 June 1830 Bishop Rosati was principal consecrator at Fr de Neckère's ordination as bishop.
At the time of his appointment as bishop of Saint Louis, the geographic area of the diocese included nearly half of the United States: Missouri, the western half of Illinois and all American territory west of the Mississippi River and north of the state of Louisiana. Its area was greater than that of the other nine United States dioceses, combined.
At the bishop's request, in 1828 the Sisters of Charity came to Saint Louis to open a hospital, the first hospital west of the Mississippi River.
The bishop and Bartolomeo Alberto Cappellari, who became Pope Gregory XVI, had been classmates. At Rosati's request, on January l3, l833 the pope signed a dispensation that permitted the Jesuits, barred by their rule from charging tuition for education, to do so at Saint Louis University.
Bishop Rosati planned for and saw built the first cathedral in North America west of the Mississippi River. His tomb is in a small building adjacent to the cathedral.
See also History of USA Provinces