On Dec. 13, 1636, a three-month-old regiment gathered for a first drill in Massachusetts. These citizens had organized themselves into military units responsible for the defense of their neighbors. And “militia” like them have served their communities, states and nation for more than 375 years, as the National Guard notes:

Citizen-soldiers have fought in every major American conflict from 1637 to present day operations in Afghanistan and Iraq. Much has changed since the “first muster,” but … the men and women of the National Guard are still defending their neighbors – and their nation.

Check out these amazingly stirring photos of the Guard in action – and occasionally at ease: