| Subject/Photo | Publication | Page |
| I am a Burlington Man adverts | BM | |
| Ice harvesting | BB12 | 6 |
| Ice house plans, Wendover, Wy. (10/22) | BB12 | 51 |
| Ice service #239414 mineral red (ex reefer) | BB12 | 7 |
| Ice service #239554, 239569, 239580-1 (ex-reefer) | BB12 | 11 |
| Ice service #239606 (ex reefer) | BB12 | 21 |
| Ice service #239607 (ex reefer) (7/78) | BB12 | 13 |
| Ice supply (Z Q&A 94-14, Z 30) | Z 31 | |
| Icing reefers by barrow Lincoln, Ne. (1948) | C 11 | 26 |
| Idler flats/gondolas Metropolis incline tracks | BB35 | 185 |
| Illini Railroad Club special LaCrosse / Prairie du Chien (7/60) | Z 59 | 30 |
| Illini Railroad Club special train poster (9/57) | C 96 | 26 |
| Illini Railroad Club 8 day fan trip loco #5632 (O-5-B) Chicago (6/62) | C 04 | 1+ |
| Illinois Midland Railroad maps Millington, Newark | Z 53 | 16 |
| Illinois Midland Railway, Oswego (Z Q&A 05-15, Z 51) | Z 53 | |
| Illinois Railway Museum CB&Q equipment display (2009) | Z 60 | 6+ |
| Illinois Zephyr Amtrak Mendota Depot (4/2001) | Z 44 | 2+ |
| Imaged Archives report (1994) | Z 30 | 1 |
| Immigration Bureau Exhibit Car #214300 | BB16 | 28 |
| Incline tracks Metropolis | BB35 | 184-5 |
| Indian red/bronze green Van Orin depot (7/60) | Z 31 | 13+ |
| Indian red/bronze green Whitton depot (6/97) | Z 37 | 8+ |
| Independent Pneumatic Tool Co. factory West Eola, and catalogue (c1925) | Z 60 | 21+ |
| Industrial Agent advert | BM | 21 |
| Industrial Works 60 ton wreckers (c1915) | BB18 | 10 |
| Industrial Works pile driver advert (c1913) | Z 58 | 18 |
| Industries Along The Q Aurora Lumber and Coal Yards | Z 61 | 16 |
| Industries Along The Q Fox River Butter Co. Aurora | Z 57 | 7 |
| Industries Along The Q West Eola Industrial Lead | Z 60 | 20 |
| Industries Along The Q Western Wheeled Scraper Co. West Eola | Z 59 | 12 |
| Ingoldsby dump cars | BB32 | 61-2/71 |
| Ingoldsby ore car as wedge plow #99230-2 C&S plan | BB38 | 112 |
| Ingoldsby ore car as wedge plow #99230 C&S (4/68) | BB38 | 53 |
| Ingoldsby ore car as wedge plow #99230 C&S (8/15) | BB38 | 53 |
| Ingoldsby ore car as wedge plow C&S | BB38 | 112+ |
| Ingoldsby wood side dump cars Denver (c1922) | C 90 | 6 |
| Injun Joe - see Zephyr #9903 | | |
| Injun Joe F-59 #193 Metra Aurora Meet Special (999) | Z 41 | 3+ |
| Inspection cars paint and numbers (Z Q&A 96-12, Z 35) | Z 35/36 | |
| Inspection engine full article | BB39 | 4 |
| Inspection engine #134 C&S (1924) | BB17 | 25 |
| Inspection engine #134 C&S (C-2L) (6/20) | BB39 | 18 |
| Inspection engine #134 C&S (C-2L) bridge exam Wendover | BB39 | 19 |
| Inspection engine #134 C&S (C-2L) diagram sheet | BB39 | 18 |
| Inspection engine #134 C&S (C-2L) headlight replaced | BB39 | 19 |
| Inspection engine #134 C&S (C-2L) with office car #902 | BB39 | 19 |
| Inspection engine #360 (A-2) (1920) | BB17 | 25 |
| Inspection engine #360 (A-2) (c1920) | BB45 | 16 |
| Inspection engine #360 (A-2) Beardstown (c1917) | BB45 | 40 |
| Inspection engine #360 (A-2) front overhang removed | BB39 | 13 |
| Inspection engine #360 (A-2) headlight replaced (c1928) | BB39 | 12 |
| Inspection engine #360 (A-2) Rock Island (1917) | BB39 | 12 |
| Inspection engine #360 (A-2) with office car #80 (c1914) | BB39 | 12-3 |
| Inspection engine #366 (A-2) (1920) | BB17 | 25 |
| Inspection engine #366 (A-2) (c1920) | BB45 | 40 |
| Inspection engine #366 (A-2) in Belmont Tunnel portal | BB39 | 20 |
| Inspection engine #367 (A-2) Lincoln coal chute (1922) | BB39 | 14 |
| Inspection engine #367 (A-2) Lincoln coaling tower (c1912) | BB45 | 40 |
| Inspection engine #367 (A-2) War Liberty Bond decorations | BB39 | 14 |
| Inspection engine #388 (A-2) (ex #129 A-1) Bridgeport, Ne. | BB45 | 41 |
| Inspection engine #388 (A-2) Bridgeport (11/29) | BB31 | 22 |
| Inspection engine #388 (A-2) Bridgeport (11/29) | BB39 | 15 |
| Inspection engine #389 (A-2) (ex #133 A-1) Lincoln (c1930) | BB45 | 41 |
| Inspection engine #389 (A-2) Brookfield (4/14) | BB39 | 84 |
| Inspection engine #389 (A-2) Lincoln (1931) | BB39 | 17 |
| Inspection engine #389 (A-2) Lincoln (1933) | BB39 | 17 |
| Inspection engine #389 (A-2) Railway Age article (1928) | BB39 | 17 |
| Inspection engine #393 (A-2) (ex #351) East St Louis (1931) | BB45 | 41 |
| Inspection engine #393 (A-2) East St Louis (1931) | BB39 | 15 |
| Inspection engine #414 (A-3 (ex B&MR #26/3200) | BB16 | 19 |
| Inspection engine #414 (A-3) (1906-12) | BB39 | 10-1 |
| Inspection engine #414 (A-3) (1912) | BB17 | 24 |
| Inspection engine #414 (A-3) (ex B&MR #26) Ashland (1906) | BB44 | 11 |
| Inspection engine #414 (A-3) (ex B&MR #26) Salt Creek, Lincoln (1912) | BB44 | 11 |
| Inspection engine #414 (A-3) Salt Creek bridge (1912) | BB39 | 11 |
| Inspection engine #425 (A-3) (1905) | BB17 | 24 |
| Inspection engine #425 (A-3) (as #1370) (1901/3) | BB39 | 5 |
| Inspection engine #425 (A-3) Burlington (1905) | BB23 | 58 |
| Inspection engine #425 (A-3) Burlington (1905) | BB26 | 17 |
| Inspection engine #425 (A-3) Louisiana, Mi. depot | BB39 | 9 |
| Inspection engine #425 (A-3) plan | BB39 | 8 |
| Inspection engine #425 (A-3) Pullman green (1906) | BB39 | 6 |
| Inspection engine #425 (A-3) with office car #91 (1906) | BB39 | 6/9 |
| Inspection engine #475 (A-2) (ex #82 A-1) Peoria, Il. (c1930) | BB45 | 41 |
| Inspection engine #475 (A-2) (ex #82 A-1) Peoria, Il. (c1930) | BB45 | 44 |
| Inspection engine #475 (A-2) (ex #82 A-1) stored Havelock (7/34) | BB45 | 49 |
| Inspection engine #475 (A-2) Galesburg (1933) | BB39 | 16 |
| Inspection engine #475 (A-2) Havelock deadline (7/34) | BB39 | 16 |
| Inspection engine #1370 (A-3) (later #425) (c1903) | BB39 | 5 |
| Inspection engine #1370 (A-3) (later #425) as converted (1901) | BB39 | 5 |
| Inspection engine #1370 (c1900) | BB17 | 36 |
| Inspection engine roster | BB39 | 20 |
| Inspection engines & trains | BB17 | 24, 36 |
| Inspection tour May 1935 consist & itinerary | BB17 | 86-87 |
| Inspection vehicle full article | BB39 | 21 |
| Inspection vehicle #96 Ford Model B Woodlawn (3/12) | BB39 | 21 |
| Inspection vehicle #305 Ford Model T Stockholm (1917) | BB39 | 33 |
| Inspection vehicle #400 C&S Buda (as Q #9000) (1935) | BB39 | 25 |
| Inspection vehicle #400 C&S Buda 619 (as Q #9000) (1935) | BB39 | 25 |
| Inspection vehicle #400 C&S Buda paint requirements letter | BB39 | 24 |
| Inspection vehicle #400 C&S Buda seating plan | BB39 | 24 |
| Inspection vehicle #1244 Plainview, Ne. (c1928) | BB27 | 34 |
| Inspection vehicle #7114 Ford Model T Fordor Sedan (c1927) | BB39 | 22 |
| Inspection vehicle #9000 (as C&S #400) Buda seating plan | BB39 | 24 |
| Inspection vehicle #9000 Buda 619 (ex C&S #400) (1935) | BB39 | 25 |
| Inspection vehicle #9000 Buda 619 | BB39 | 24-6 |
| Inspection vehicle #9001 Ford Carson (4/45) | BB39 | 31 |
| Inspection vehicle #9001 Ford Red Oak (c1945) | BB39 | 31 |
| Inspection vehicle #9001 Ford Villisca (9/51) | BB39 | 31 |
| Inspection vehicle #9003 Buda 619 BP (1933) | BB39 | 26 |
| Inspection vehicle #9003 Buda 619 | BB39 | 24-6 |
| Inspection vehicle #9003 Chrysler station wagon Guernsey | BB39 | 34+ |
| Inspection vehicle #9013 Ford Model T Sterling (6/30) | BB39 | 28 |
| Inspection vehicle #9014 Ford Model T (c1933) | BB39 | 28 |
| Inspection vehicle #9017 Ford V-8 (1934) | BB39 | 30 |
| Inspection vehicle #9021 Buick Special Centralia (8/65) | BB39 | 32 |
| Inspection vehicle #9021 Chrysler Plymouth Denver (4/68) | BB39 | 34+ |
| Inspection vehicle #9021 Ford V-8 Fordor (c1938) | BB39 | 29 |
| Inspection vehicle #9029 Buick Special (1955) | BB39 | 33 |
| Inspection vehicle #9029 Ford V-8 West Burlington (10/37) | BB39 | 30 |
| Inspection vehicle #9038 Ford V-8 Alliance (1/47) | BB39 | 32 |
| Inspection vehicle #9039 Ford V-8 Douglas (6/45) | BB39 | 32 |
| Inspection vehicle #9076 Buick Oregon, IL depot (1952) | Z 57 | 4 |
| Inspection vehicle #B-29 UP Buda 619 towing #DC-1 UP | BB39 | 60 |
| Inspection vehicle #M-61 NP Buda towing detector car (9/38) | BB39 | 44 |
| Inspection vehicle article Railway Age (1917) | BB39 | 33 |
| Inspection vehicle flanged pneumatic tyres (c1938) | BB39 | 29 |
| Inspection vehicle Ford Model T Beardstown | BB39 | 22 |
| Inspection vehicle Ford Model T Centralia | BB35 | 37 |
| Inspection vehicle replacement authority (2/34) | BB39 | 23 |
| Inspection vehicle train orders | BB39 | 35 |
| Inspection vehicle with Hi-Rail wheels | BB39 | 31-4 |
| Insulated box car decal plans | Z 11 | 12 |
| Insulated box car paint (Z Q&A 92-16, Z 27) | Z 27 | |
| Insulated box car roofs (Z Q&A 99-8, Z 41) | Z 41 | |
| Interlocking diagram Seminary Street Tower | Z 37 | 16+ |
| Interlocking machine Union Avenue Tower, Chicago (5/48) | C 11 | 8 |
| Interurban #401 CA&E Broadway, Aurora, underpass | BB46 | 64 |
| Iowa Branch Lines timetables (1922/4) | BB30 | 44-7 |
| Iowa Branch Lines timetables (1928/1931) | BB30 | 51-2 |
| Iowa Model Steam Engineers, Mt Pleasant, Io. (2008) | Z 58 | 6+ |
| Iron Horse 400 special train (1/62) | C 96 | 2 |
| Ira Eigsti photos of Buda, Il. full article | BB41 | 78 |
| Isabella CB&Q tugboat Metropolis (12/17) | BB35 | 182-3 |