A native of Bohemia, John entered the seminary and was nearing ordination when he departed for the United States. He joined the Redemptorists and served as a priest in New York, Maryland and Pennsylvania. In 1852 he was named the fourth bishop of Philadelphia. He founded more than 50 churches and greatly expanded Catholic education. John had a fondness for immigrants and knew six languages. His pastoral zeal was evident up to his last moments of life. He collapsed and died in the street at age 48.