In the early 1820s the Bishop of the
Louisiana Territory,
Louis Du Bourg, invited the
Society of Jesus to come to the newly admitted state of
Missouri. Van Quickenborne volunteered, and was accompanied by six young
Belgian Jesuits and six
African-American enslaved people: Moses and Nancy Queen, Thomas and Molly Brown, and Isaac and Susan Hawkins, each husband and wife. Thomas and Molly Brown and Moses and Nancy Queen were in their 40s; while Thomas and Molly Brown were childless, Moses and Nancy Queen were forced to leave their children.
Flemish priest
Charles de la Croix came to
Florissant, Missouri in 1818. The area was predominantly French-speaking. By the time the Jesuits arrived in early June 1823, he had nearly completed a brick church, started a farm. Van Quickenborne was placed in charge of
Sacred Heart Parish. That same year, he founded
St. Stanislaus Seminary, on the farm on the outskirts of town. It was named for Jesuit
Stanislaus Kostka. The Queens, Browns, and the Hawkins worked the farm to support the mission. The parish did not have a regular church building yet, so the members met at various homes for mass. The later became the cathedral seat of the
Archdiocese of Dubuque. Researchers have noted van Quickenborne's refusal to address reports of abuse of enslaved African Americans in Missouri, when he served as superior. He was at one point involved in an altercation with two women who were "furious" with his tepid response. ==St. Regis Seminary==