St. Mary's Institute-National Register of Historic Places Historical Narrative, 2007

Detailed historical and architectural narrative prepared in connection with the National Register documentation for St. Mary's Institute. Covers the congregation's European origins and migration, establishment and architectural development of the O'Fallon motherhouse, Assumption Parish and O'Fallon's German-American community, educational institutions, water infrastructure, international missions, and the Ecclesiastical Art Department. Particular attention is given to Sister Hiltrudis Powers, her liturgical designs, stained glass, metalwork, and the 1962–1964 chapel renovations. The narrative concludes with the 1997 sale of portions of the property to the City of O'Fallon and an assessment of the site's historical significance.