In downtown Portland, Oregon there is a small urban park with a statue of an infantryman from the 2nd Oregon Volunteer Infantry, who served during the Spanish-American War and the so called Philippines Insurrection from 1898 on. These were the true militia. Not National Guard, but rather State of Oregon soldiers who volunteered to serve the nation during time of war. The National Guard, which is for practical purposes a federal military force on loan to the various states, discriminates for membership on much the same basis as the regular Army and reserves. There was no National Guard as such prior to about 1907. There is no sense of general population participation in the traditional meaning of the word militia. Now, many states have what are referred to as State Guards. These are military formations that fall under the state Military Departments and are under the executive command of the respective Governors. In some states they are large and well organized and provide valuable service to the community. In other states they are virtually unknown and and tiny. In many states they do not exist at all. Such a State Guard exists in my state, yet not one state legislator of the 20 or more I have asked has ever heard of it. Several became indignant regarding my allegation of the existence of the State Guard.
Let us go further back in history. During the decades of the American frontier, manifest destiny, and wars with neighboring nations, European empires and native nations there was an ongoing need for a rapid response military formation in almost all rural and some urban communities that was met by local and popularly organized military units with elected leaders. These formations often maintained armories, communications and transport systems. The only legal authorization for their existence lay with the 2nd Amendment of the US Constitution and the respective equivalent passages of the constitutions of the various states. Yet now, such formations are either quasi-legal, illegal or non-existent. Why? Certainly the risk of foreign terrorist acts, domestic upheaval or enemy military attack has never disappeared.