John Janssen
John Janssen was the first Roman Catholic bishop of Belleville, Illinois, serving from 1888 until his death in 1913.
Janssen was born in Keppeln, Rheinish Prussia, and studied at the seminaries of Gaesdonck and Münster. He accepted an invitation from Bishop Henry Damian Juncker in 1858 to join the Diocese of Alton in the United States. After arriving in Illinois, he was ordained to the priesthood on November 19, 1858.
Janssen then served as pastor of Sts. Peter and Paul Church in Springfield until 1863, when he became secretary to Bishop Juncker and chancellor of the diocese. He was vicar general of the diocese from 1870 to 1886, also serving as pastor of St. Boniface Church in Quincy from 1877 to 1879.
Following the division of the Alton Diocese into the dioceses of Alton and Belleville, Janssen was appointed Bishop of the new Belleville Diocese on February 28, 1888. He received his episcopal consecration on the following April 25 from Archbishop Patrick Feehan, with Bishops John Joseph Hogan and Louis Mary Fink, O.S.B., serving as co-consecrators. By 1902 the diocese contained 104 churches, 94 priests, 64 parochial schools and 50,000 Catholics.
Janssen later died at age 78.