> The Militia Act of 1903 divided what had been the militia into what it termed the "organized" militia, created from portions of the former state guards to become state National Guard units
yes, the present national guard is very much a government entity, and held to the same training standards as federal armed forces. they regularily hold joint training.
the people at large however are not prevented from forming a militia or a posse, or volunteering to be deputized by a local police force.
the common element is that they are responding to a domestic threat originated from government activities.
the original conception of american government insists that the government exist at the consent of the governed, in service of the governed, and this consent is revoked when that government fails to colour inside the lines when interpreting the constitution of the USA
https://en.wikipedia.org/wiki/Militia