Since 1956, the Archdiocese of Saint Louis has sent its own priests of the Archdiocese as missionaries to La Paz, Bolivia in South America. Due to the shortage of native priests in the Archdiocese of La Paz, Archbishop Abel Antezana requested that Archbishop Joseph Ritter send priests from Saint Louis to serve in La Paz.

Archbishop Ritter said that the decision to send priests of the Archdiocese of Saint Louis as foreign missionaries was the most important decision in his twenty-three years as a bishop. This has been a special blessing for the priests, as well as for other missionaries, whether the Sisters of the Most Precious Blood in O’Fallon, Missouri, or the Papal Volunteers in Latin America (PAVLA).