The Library Acquisition Patterns (LAP) project was undertaken with the support of The Andrew W. Mellon Foundation with the aim of examining trends in US academic libraries’ book purchasing. The findings of this report consist of two distinct areas: 1) an analysis of library book acquisitions within the specified sample for fiscal year 2017 at 124 US academic institutions, and 2) a trend line analysis of print and e-books acquired within the specified sample, the university press presence in these libraries, and the leading vendors of books at 51 US academic institutions for fiscal years 2014 through 2017. While these samples are not representative, they afford a broader overview of the acquisitions patterns and practices of US academic libraries than we believe has ever been conducted to date.