Militia activism has been a part of the American political and social landscape since the beginning of the Republic. Beginning with the Anti-Federalists during the founding period, there has always been a group of Americans who believe that patriotism obliges them to guard our liberty against what they see as a corrupt federal government. Although the names of these citizen groups have changed over the years—Anti-Federalists, Minutemen, Militias—their belief in a government of limited powers has remained the same. There have been two periods in the twentieth century when militias have been brought under the scrutiny of popular opinion and academic analysis: the 1960s, when groups like the Order and the Posse Comitatus were formed against the background of the civil rights movement and Cold War narratives; and the 1990s, with events like the Ruby Ridge standoff in Idaho in 1992 and the bombing of the Federal...