Mattoon, IL, USA / MyRadioLink.com Illinois State Museum. Illinois State Museum Joins Global Conversation on the Return of Cultural Heritage SPRINGFIELD, Ill. – The Illinois State Museum (ISM) will join museums, universities, and museum professionals across five continents virtually April through June to present a four-part conversation series on repatriation and the return of cultural heritage. Due to colonization practices, museums hold in their collections ancestors, belongings, and treasures belonging to Indigenous peoples. As museums atone with past practices and engage Indigenous communities, they are beginning to return some of their holdings to the cultures where they belong. However, a viable, international approach to repatriation has yet to be found.