This poster takes a retrospective look at the original collection at the University of Illinois at Urbana-Champaign, and illustrates the extreme growth in the collections over the years. The University Library began with just 1,083 volumes in 1868, and that number nearly quadrupled in two years, increasing the collection to 4,051 volumes by 1870. Now, 145 years later, the collection has exploded to contain more than 13 million volumes. What was the composition of the original collection, and where did it go? Other than size, how did that collection differ from the collection of today? Does this tell us anything about the collection of tomorrow? This poster will explore the collection development policies and guiding principles at the University of Illinois at Urbana-Champaign and how those have changed and have shaped the collection over time. We will provide a collection analysis, as well as graphical representations of the collection, looking more closely at the contents of this research library collection, both in the Library’s infancy and today, and discover trends that have developed over time. As the Library approaches its sesquicentennial, we must look more closely at what it meant and continues to mean to have a premier research collection, thinking critically about where and how our collection should grow from here.