Complex sentence: Lilly was also known for his significant collection of rare books and manuscripts, which he donated to Indiana University to form the core collection of the Lilly Library, located on the IU campus in Bloomington, Indiana.
Split into simpler sentences: Lilly was also known for his significant collection of rare books and manuscripts, which he donated to Indiana University. It formed the core collection of the Lilly Library, located on the IU campus in Bloomington, Indiana.