It should not surprise you to learn that Chicago ranks with New York, Los Angeles, Washington DC, New Haven and Boston among the U.S. cities with the most medieval manuscripts, with just over 900 leaves and codices in eight public collections, at last count. The manuscripts can be found all over the city, in the following institutions: The Adler Planetarium and Astronomy Museum, The Art Institute of Chicago, The Chicago History Museum, Chicago Theological Seminary, DePaul University, The Newberry Library, the University of Chicago, and Northwestern University (technically in Evanston, I know, but close enough to count). Let’s take a closer look at a few of these collections.
Some of the manuscripts and leaves belonging to the Art Institute of Chicago have been digitized; you can find them here. Because the search engine doesn’t allow for filtering by date, however, this set includes post-medieval leaves and cuttings. A few of the cuttings are catalogued as “14th century or modern,” and in fact without seeing the cuttings in person it’s hard to tell it they are modern reproductions or original medieval initials. Judge for yourself:
Nothing about this initial looks particularly suspicious to me (the green and yellow are a little atypical, but not too alarming, especially if the original manuscript had been illuminated in England), but I’d want to examine the initial in person before rendering an opinion. In particular, I’d want to look at how the gilt was laid down (according to medieval or modern techniques), see what’s on the dorse of the initial (if it’s blank, that would suggest a modern reproduction), examine the quality and preparation of the parchment (if it’s particularly white and smooth, that might also suggest a modern origin), and study how the pigment has affected the parchment (sometimes green can bleed through after a few centuries to be visible from the other side). It was quite common in the early twentieth century for artists to reproduce medieval initials, not necessarily to pass off as original (there certainly were forgers about, the most infamous being The Spanish Forger, who we will get to in a few weeks). There is a notorious example of just such a forgery at the University of Chicago.
The U. Chicago manuscript known as The Archaic Mark (a.k.a. MS 972) was until recently thought to be a fourteenth-century manuscript preserving ancient readings of the Gospel, which had made it an important exemplar for critical editions of the Greek text. When it was digitized and made available to scholars worldwide in 2006, however, irregularities in the script and illustrations led some scholars to question its authenticity. The University commissioned a detailed scientific analysis of the pigments, ink and support to be undertaken in part by Abigail Quandt (of the Walters Art Museum and the primary conservator who worked on the Archimedes Palimpsest). The study concluded decisively that the manuscript was a forgery: carbon-dating established that the parchment dated to the 15th-17th centuries, while pigment analyses – of the zinc white and a “cream” tone in particular – proved that the manuscript had to have been written in the late nineteenth or early twentieth century. Often there is no way to know if an inauthentic manuscript was created as an homage or as a deliberate forgery, although the intentional aging of the Archaic Mark suggests that in this case the deception was deliberate. These videos explain the analyses and conclusions:
http://news.uchicago.edu/multimedia/chicagos-archaic-mark-ms-2427-report-results-chemical-codicological-and-textual-analysis (the short explanation)
http://news.uchicago.edu/multimedia/university-chicago039s-quotarchaic-markquot-remarkable-manuscript-treasure-or-modern-day- (the long and more technical explanation)

King David at Prayer, Prayerbook of Anne of Brittany (Florence, 1499) (Chicago, Newberry Library, MS 83)
Let’s head to the The Newberry Library, where we will find more than 250 medieval and Renaissance manuscripts, images of some of which can be found in the digital exhibition French Renaissance Gems. The manuscripts have been thoroughly catalogued in print by Paul Saenger (A Catalogue of the Pre-1500 Western Manuscript Books at the Newberry Library (Chicago: University of Chicago Press, 1989)), and many are reproduced in the recent monograph, An Introduction to Manuscript Studies by Ray Clemens and Timothy Graham. One of the highlights of the collection is this prayerbook created for Anne of Brittany, Queen of France with Louis XII, in 1499. In the image at left, the opening of the Penitential Psalms, King David is shown at prayer within the letter [D] (for “Domine ne in furore,” the beginning of Psalm 6). Above, two putti hold a medallion with the Greek letters “I∑ X∑” (abbreviating “Ihesus Christus”). The margins illustrate the Annunciation, with the Angel Gabriel at the left addressing the Virgin Mary seated at the right. The arms and monogram in the lower margin are not Anne’s, having been added by a sixteenth-century owner. There are several extant manuscripts known to have been commissioned for Louis and Anne, and they are all, like this one, sumptuous masterpieces.
Although Chicago gets a lot of attention as far as medieval manuscripts in Illinois are concerned, I want to make a few non-Chicago stops before we leave the state. The University of Illinois in Urbana-Champaign has a significant collection of 96 codices and 88 leaves, most of which have been catalogued but not yet digitized (note that the library uses 1650 as their early-manuscript cutoff date, while I prefer 1600). The exceptions are UIUC MS 81, a fourteenth-century manuscript of Le Roman de la Rose, and UIUC MS 65, a fifteenth-century English translation of Bonaventure’s Vita Christi, both of which are available online.
And finally, I will keep my promise to point out manuscripts in unexpected places. Here’s one: a document signed by John Chisull, Bishop of London, in 1274 that belongs to the Abraham Lincoln Presidential Library in Springfield, Illinois. It’s item #44 in this handlist. I was disappointed, however, to learn that the document was never owned by the 16th President of the United States. It was part of an autograph collection compiled by Jesse Jay Ricks, a Chicago lawyer who died in 1944.