I
- The ice's frame, in the survey's own names The Land
- The imperial-door mechanism: the Canadian plant as the door to Empire trade Exports
- Improvised ingenuity: the dragged-boat test — a named gap, settler named Famous Stories & the Record
- Incorporation: a town on the map for ninety years before it was a town in law Government
- The independent thread and the festival: the River Bend course at boundary, the town thread negative Film
- “Indiana's oldest zoo,” tested — and the name course, with the 2025 date corrected Zoo
- The Indianapolis line in three forms, never merged: a starter who built his car, a builder who raced, and the test-driver residue Racing
- The Indigenous-authored legend book, whole: Simon Pokagon's shelf Famous Stories & the Record
- Industrial buildings as architecture: the mill seats and the Ash Road creamery, at survey size Architecture
- Industrial fame on the ground: the proving ground, the sign written for airplanes — and this ground's unfamous mill seat Famous Landmarks
- Industrial Fortunes by Sector (L17·6) Wealth
- Industrial Revolution Section
- Industrial superlatives at source: the creamery's numbers, and the mills' Famous Stories & the Record
- Industry-defining inventions: the strands separated — designed by residents, seated in Elkhart Inventors & Inventions
- Influencers & Digital Creators Section
- The infrastructure winners: carrier hotel and fiber ring Dot-Com Era
- The institutional and campus tables: the campus sandwich, the county's sugar camp, and school feeding — a named gap at full honesty Food & Drink
- The institutional block held whole: Beech Road and Lincolnway as one built fact Architecture
- Institutional origin oddities: the class run whole, and negative on this ground Famous Stories & the Record
- The institutional production houses in succession: Golden Dome, Fighting Irish Media, and WNIT's producers Film & TV Producers
- The institutions the community built: Hering House, the NAACP chapter, and the Allens Black History
- The intermediate-goods trade: lumber out, flour out, implements in — the means of the next industry the record supports Industrial Revolution
- Intermodal, and the numbers as a series Airports
- The interurban conversion: it exists — on the north line. On Osceola's line, the grade became a bus route Bike Trails
- The interurban test: a regular station at mile 10.1 Transportation
- Invention claims at the patent record: Nathan Young's empty file, and one Osceola hull Famous Stories & the Record
- The inventor-founder, the branch-plant keeper, and the paired founders — at the strength each returns Founders & CEOs
- Inventors & Inventions Section
- Investigators and organizations: who actually worked this sky, and what they filed UFO Sightings
- The Irelands: first justices, a rival plat, and a memoir that will not sign its author Notable People