Abstract: This is a print edition of Professor Jeremy Sheff's 2019 build of Open Source Property, a free online casebook for the first-year Property Law course at American law schools. A free digital edition of this text is available for download from www.opensourceproperty.org. Open Source Property is copyright 2015-16 by Stephen Clowney, James Grimmelmann, Michael Grynberg, Jeremy Sheff, and Rebecca Tushnet. It may be reused under the terms of the Creative Commons Attribution NonCommercial 4.0 International license, https://creativecommons.org/licenses/by-nc/4.0/.