- University of Illinois at Chicago66,994
- Illinois State University21,424
- University of Illinois at Urbana-Champaign Library18,916
- Southern Illinois University Carbondale17,418
- Chicago Public Library15,204
- Newberry Library12,944
- Illinois Wesleyan University9,579
- Illinois State Library8,046
- Park Ridge Public Library6,931
- Eastern Illinois University6,410
- West Chicago Public Library District6,378
- Northern Illinois University6,291
- Western Illinois University5,906
- Gail Borden Public Library District5,736
- Pullman State Historic Site5,691
- North Park University5,670
- Knox College4,841
- Bess Bower Dunn Museum of Lake County4,545
- Quincy Public Library4,233
- Lewis University4,127
- University of St. Francis3,927
- Bradley University3,779
- Augustana College3,756
- Elgin History Museum3,501
- Sterling Public Library3,300
- Southern Illinois University Edwardsville3,262
- Meadville Lombard Theological School2,996
- Chicago History Museum2,856
- Trinity International University2,719
- Huntley Area Public Library2,453
- Urbana Free Library2,385
- Cook Memorial Public Library District2,061
- Graham Hospital School of Nursing2,048
- Garrett-Evangelical Theological Seminary1,918
- Roosevelt University1,849
- University of Illinois at Springfield1,825
- Elgin Community College1,821
- Arlington Heights Memorial Library1,724
- Highland Park Historical Society1,661
- Governors State University1,650
- Orland Park Public Library1,581
- Illinois State Historical Society1,566
- Skokie Public Library1,515
- Illinois Prairie District Public Library1,381
- Madison Historical - Southern Illinois University Edwardsville1,369
- Des Plaines Public Library1,331
- Galena Public Library District1,190
- Flora Public Library1,123
- Millikin University1,088
- University of Saint Mary of the Lake990
- Abraham Lincoln Presidential Library and Museum951
- Towanda District Library840
- Cary Area Public Library835
- Coal City Public Library District828
- Roselle Historical Foundation775
- Dominican University769
- Saint Xavier University740
- Illinois State Museum734
- Cherry Valley Public Library District705
- Vespasian Warner Public Library District623
- Arthur Public Library488
- Gail Borden Public LIbrary District479
- Lake Forest Academy470
- Lincoln Library463
- Mount Prospect Public Library450
- Lincoln Land Community College445
- Elmwood Park Public Library408
- Benedictine University407
- Illinois Eastern Community Colleges361
- Naperville Public Library343
- DePaul University. Special Collections and Archives342
- Eisenhower Public Library District322
- Eureka Public Library District, Eureka Illinois313
- North Suburban Library District299
- Ernest Hemingway Foundation of Oak Park in cooperation with the Oak Park Public Library297
- Plainfield Public Library285
- Southeast Chicago Historical Society271
- Illinois State Archives264
- National-Louis University254
- Ella Johnson Memorial Public Library District250
- Monmouth College248
- Northeastern Illinois University224
- Melrose Park Public Library223
- Rockford Public Library213
- Sparta Public Library211
- Fountaindale Public Library District205
- Peoria Public Library200
- Plainfield Public Library; Plainfield Historical Society; Wheatland Township Assessor198
- Glenview Public Library196
- Highland Park Public Library188
- Chicago Ridge Public Library, Chicago Ridge, Illinois184
- Eureka College184
- Evanston Public Library179
- Illinois Fire Service Institute175
- Thomas Ford Memorial Library172
- Indian Trails Public Library District153
- Henderson County Historical Society Museum - Raritan, Illinois152
- The Art Institute of Chicago147
- Itasca Community Library133
- Lewis & Clark Community College131
- Lenhardt Library of the Chicago Botanic Garden121
- Pritzker Military Museum & Library118
- St. Charles Public Library104
- Illinois Mathematics and Science Academy89
- Columbia College Chicago84
- Aurora Public Library83
- Park Forest Historical Society76
- Midway Village and Museum Center74
- Ella Johnson Memorial Public Library District in cooperation with the Hampshire Historical Society67
- Wilmette Public Library63
- Erikson Institute61
- Donald Horn60
- Illinois State Fair Museum60
- Deerfield Public Library59
- McLean County Historical Society55
- Oak Park Public Library53
- Harper College51
- Madison County Genealogical Society50
- La Grange Public Library49
- Algonquin Area Public Library District46
- Rush University44
- St. John's College Department of Nursing, Springfield, Illinois41
- Fenton High School District 10038
- Illinois Institute of Technology37
- Joliet Public Library36
- Lake Forest Library36
- Polo Public Library District36
- Elgin History Museum; https://elginhistory.org35
- Elmhurst College32
- Illinois Center for the Book27
- Blessing Health Professions Library24
- Centralia Regional Library District24
- Lombard College24
- Rosalind Franklin University of Medicine and Science22
- Mount Olive Public Library21
- MacMurray College20
- Woodstock Public Library20
- Arlington Heights Memorial Library with materials owned by the Arlington Heights Historical Society17
- Niles Public Library District16
- Bensenville Community Public Library14
- Lisle Library District13
- Geneseo Public Library District11
- Wheaton Public Library10
- Edwardsville Public Library7
- Plainfield Public Library District6
- Trinity Christian College6
- Park District of Highland Park5
- Sterling Morton Library5
- Des Plaines Suburban Times4
- Des Plaines History Center2
- Gail Borden Public Library District; Elgin Academy1
- Institute of Jamaica1
- Plainfield Public Library District, Plainfield Historical Society1
