In the early 1830s, Fr. Benedict Roux reported only nine Catholic families living in western Missouri. The arrival of Catholic missionaries, most notably Fr. Bernard Donnelly in 1845, signaled the permanency and success of the Catholic Church in the area. As European upheavals facilitated the immigration of Irish and German Catholics, Catholicism continued to expand and flourish. The Catholic population in the region was enough to warrant the establishment of the Diocese of Kansas City on September 10, 1880. The immigration of Sicilian and Italian immigrants in the late 19th century as well as Hispanics and Vietnamese Catholics in the 20th century further consolidated the strength of the Catholic Church in western Missouri. On August 29, 1956, the Holy See incorporated part of the Diocese of St. Joseph into the former Diocese of Kansas City, creating the Diocese of Kansas City-St. Joseph. From these humble roots developed a diocese of nearly 124,000 Catholics in 91 parishes and 10 missions. This book traces the development of Catholicism within Kansas City, from its modest beginnings through the second renovation of the Cathedral of the Immaculate Conception in 2003.