In colonial times, the Thirteen Colonies used a militia system for defense. Colonial militia laws—and after independence those of the United States and the various states—required able-bodied males to enroll in the militia, to undergo a minimum of military training, and to serve for limited periods of time in war or emergency. This earliest form of conscription involved selective drafts of militiamen for service in particular campaigns. Following this system in its essentials, the Continental Congress in 1778 recommended that the states draft men from their militias for one year's service in the Continental Army; this first national conscription was irregularly applied and failed to fill the Continental ranks.