The military organization we know today as the National Guard came into existence with a direct declaration on December 13, 1636. On this date, the Massachusetts General Court in Salem, for the first time in the history of the North American continent, established that all able-bodied men between the ages of 16 and 60 were required to join the militia. The North, South, and East Regiments were established with this order. Simply stated, citizen-soldiers who mustered for military training could be and would be called upon to fight when needed.
Today, the descendants of these first regiments - the 181st Infantry, the 182nd Infantry, the 101st Field Artillery, and the 101st Engineer Battalion of the Massachusetts Army National Guard – share the distinction of being the oldest units in the U.S. military. December 13, 1636, thus marks the beginning of the organized militia, and the birth of the National Guard's oldest organized units is symbolic of the founding of all the state, territory, and District of Columbia militias that collectively make up today's National Guard.