I
- Ice, coal, and the carrying trades Businesses & Banks
- The Immigrants: Kathryn Field, 1993 Arts
- The Independence Day Celebration Events Calendar
- Indian Ridge Plaza: the first ring around the mall Malls & Shopping
- The Indiana City Hotel: a hotel that became a school, 1853 Hotels & Motels
- Indiana City's paper geography: the park that was a power reserve, and the squares never built Neighborhoods
- Indiana University South Bend — Schurz, Bowen, and the Located Directory Sources
- The industrial buildings at survey size Architecture
- Industrial Revolution Section
- Influencers & Digital Creators Section
- Influenza: the autumn of 1918, and the counted return of January 1920 Epidemics & Public Health
- Inside the Northern Indiana system: Mishawaka's miles, 1899-1940 Public Transit
- Institute No. 1, the Main Street school, and the high school's opening, 1868–1878 Schools & Colleges
- The institutions' cameras: newspapers and companies Photographers
- The interurban through Mishawaka: to Elkhart and Goshen, 1898-1934 Public Transit
- The Interurban Trolley: the cross-county buses and the Yellow Line to Mishawaka, 2006 to today Public Transit
- The interurban, at pointer — and the losses ledger Railroads
- Into market: the land office and the first entries Land Surveys & Titles
- Inventors & Inventions Section
- Inventors & Inventions: Open Questions Inventors & Inventions
- Investigators and organizations: the local record UFO Sightings
- Iraq and the armor crisis AM General
- Irene Vernon: Louise Tate, and the three ways she left Notable People
- The Irish: the mother parish's first people Communities
- The iron company's engine and the volunteer companies Fire & Public Safety
- The iron system: ore, charcoal, and water Industrial Revolution
- The Italian club bands: the circuit that trained the trumpets Music
- The Italian north side: east of Main, north of Mishawaka Avenue Neighborhoods
- The Italian south side: between the tracks, Thirteenth, Spring and Union Neighborhoods
- The Italians: two sides of town, two clubhouses, one hometown in Calabria Communities