For this capstone project, we explored a collection development challenge for Washington State's open data program. Specifically, we investigated data selection practices at leading government open data programs in the United States. “Selection” in this context refers to the range of practices that determine what and how much data is opened and ultimately published on open data portals. Our final report, which summarizes the state of data selection and best practices across the United States, will help Washington State Library connect individuals and communities to data that will help them flourish.