Every era has its unique challenges, but history may still offer lessons on how law empowers and restrains presidents. This Essay examines how President Lincoln negotiated the tension between crisis authority and the rule of law. This analysis requires an appreciation of the wartime imperatives, institutions, and political forces confronting Lincoln, as well as the legal framework in which he acted. Similar issues unexpectedly arose in our times in the aftermath of the 9/11 attacks, providing a new point of comparison with Lincoln’s era. We need to better understand how political actors and institutions, the media, and public opinion can provide support for legal norms, lest we place all of our trust in presidential self-restraint and good judgment.