Headquartered in St. Louis, Missouri, since the original split into Eastern and Western Provinces in 1888, the Western Province of the Vincentian Priests and Brothers has remained throughout history to contain all the regions in the United States west of the Mississippi River.
St. Louis was one of the first locations of Vincentian mission in the United States, and from the early days of St. Mary’s of the Barrens Seminary— the seminary established by some of the first Vincentians to live and work in the United States— the Western Province set out to accommodate for the needs of the immigrant Catholic community just as the Eastern Province was doing at the time. As there was a need for better education among the groups Vincentians were serving, the Western Province had a focus on the establishment and betterment of seminaries and schools. The most successful of these, originally a high school built on the north side of Chicago, later became DePaul University, now the largest Catholic university in the United States.