This class covers the constitutional role of state militias as the first line of defense against foreign invasion and domestic tyranny. It emphasizes that Congress, not the president, has the power to call forth the militias, and only under three limited circumstances: executing the laws of the Union, suppressing insurrections, and repelling invasions. The lesson shows how the Framers intended militias — organized, armed, and trained by the states themselves — to be a bulwark of liberty, not standing armies at the president’s disposal.