The Illinois State Historical Library was the first Illinois institution to participate in the USNP, and received a planning grant from the National Endowment for the Humanities to develop a survey to assess the state's newspaper collections. ISHL staff sent more than 4,000 surveys to libraries, newspaper publishers, historical societies, genealogical organizations, and anyone whom they learned might own newspapers. With the planning phase completed in March 1989, the Illinois Newspaper Project team received another grant from NEH to undertake the cataloging and inventorying work, with technical assistance provided by the Library of Congress. The INP began inventorying and cataloging the newspaper collections at the ISHL in Springfield, Illinois and at the Chicago Historical Society in Chicago. This work took the INP six years to complete.
After the fieldwork on the collections at ISHL and CHS was completed, the INP relocated its office to the University of Illinois at Urbana-Champaign Library in Urbana, Illinois. Staff at CHS continued inventorying and cataloging other collections in northeast Illinois, and the UIUC-based staff began inventorying and cataloging the newspaper collections at UIUC. INP staff completed work on the collection at UIUC in three years. When this was completed, they began fieldwork in east central Illinois.
INP staff at UIUC completed fieldwork in east central Illinois, and by 2005, the Midwestern region of Illinois was also completed. The CHS team took responsibility for inventorying and cataloging newspaper collections found in the northwest part of the state. By the end of 2007, UIUC INP staff had completed the southernmost region of the state, and also began preservation microfilming of unique Illinois newspapers from the UIUC Library collections and other institutions in the state. Staff at the Chicago History Museum completed fieldwork in northeastern Illinois.
INP staff at UIUC completed fieldwork in southeast Illinois. The staff at CHM completed fieldwork in northwest Illinois, closing their project in April 2009. With the completion of fieldwork in downstate Illinois, the staff at UIUC began the task of re-inventorying the newspaper microfilm collection at the Abraham Lincoln Presidential Library in Springfield, and also continued preservation microfilming of unique Illinois newspapers. In June 2009, UIUC Library received funding under the National Endowment for the Humanities' National Digital Newspaper Program to digitize culturally significant Illinois newspapers. Titles digitized as part of this program are hosted on the Library of Congress' Chronicling America website.
The Illinois Newspaper Project, as part of the USNP, completed work in July 2010. To date, INP staff has inventoried and cataloged 21,000+ U.S. newspaper titles, added 26,000+ holdings records to the newspaper union list in OCLC, and microfilmed almost 2,250,000 pages, becoming an important resource for scholars, genealogists, and ancestry enthusiasts. In 2010, the INP exhausted its grant funding for preservation microfilming of unique Illinois newspaper titles, having preserved on microfilm almost 500 titles. In July 2013, the INP received funding under the NEH to continue digitizing culturally significant Illinois newspapers until August 31, 2015.