There is an item available online to Univ. of MO patrons, is that accessible through ILL? the William Lynch Letter by Wm. Cobb. found through the
Thank you for asking! Generally speaking, databases and electronic collections held by other libraries are not available through inter-library loan. However, there may be other options you can pursue. For one, if you place an inter-library loan request for a copy of the article, there may be a library that has a print version available. It appears that the UMSL document appears in an online version of the Encyclopedia of Race and Racism, 2013, ISBN 9780028661957, pp. 282 - 284.
Given the complex history of the Willie Lynch letter/speech, its spread and cultural impact, there are quite a few books and articles that reproduce it and discuss it in part or in full. Omaha Public Library has two titles, The Willie Lynch Letter & The Making of a Slave and The Curse of Willie Lynch, that may be of use to you. The St. Louis Black Pages, where the letter may have been first published, still hosts a transcript. Dr. William Jelani Cobb, author of the article that you cited from the UMSL catalog, discusses the letter in several articles online.
Please feel free to call 402-444-4857 for questions specific to inter-library loan, or 402-444-4800 for other questions, and thank you for using AskOPL!