This article represents background material that can be used e along with the "United States v. Windsor" case to teach Constitutional Law (particularly federalism, due process, and equal protection) and the legal debate surrounding same-sex marriage in America. Professors may assign it as background reading before or after a Constitutional Law lecture. Prelecture distribution provides students with a solid background and facilitates understanding of tough legal/policy concepts. Postlecture distribution allows the Supreme Court opinions to speak for themselves, allows students to ponder any implications of the rulings without outside influence, and allows the article to serve as reinforcement. Additionally, professors can refer to this article as they prepare to teach same-sex marriage or Constitutional Law more generally. This article is designed for professors to tailor their lectures to the constitutional law issues most pertinent in their syllabus. This article discusses the Due Process and Equal Protection Clauses in depth. Also discussed are the Full Faith and Credit Clause (FF&C Clause) and the standing and incorporation doctrines. Finally, in the interest of fairness, many professors evaluate both the majority and dissenting opinions and the lower court opinions in these important cases--a task this article undertakes as well. This article encourages students to plug into the provocative issues in the "Windsor" case and learn essential constitutional law concepts simultaneously.