O Fallon City
O'Fallon City Hall is located at 100 North Main Street, O'Fallon, MO 63366; phone: 636-240-2000.
O'Fallon as described in 1941 
O'Fallon was founded in 1857 and named for Major John O'Fallon, St. Louis capitalist and director of the old North Missouri Railway. The group of Flemish-type buildings near the center of the village comprises The Convent of the Congregation of the Sisters of the Adoration of the Most Precious Blood, mother house of an educational order noted for its embroideries.