A Well Regulated Militia, being necessary for the security of a free state ……
Our Nation was won through the actions of the Continental Army, Well Regulated Militias and the French Navy
And surprising how few understand the terms and applications of such from 250 years ago.
Basic Definition and Meaning of "militia";
...
The history of militia in the
United States dates from the colonial era, such as in the American Revolutionary War.
[118] Based on the English system, colonial militias were drawn from the body of adult male citizens of a community, town, or local region. Because there was no standing English Army before the
English Civil War, and subsequently the English Army and later the British Army had few regulars garrisoning North America, colonial militia served a vital role in local conflicts, particularly in the
French and Indian Wars. Before shooting began in the
American War of Independence, American revolutionaries took control of the militia system, reinvigorating training and excluding men with
Loyalist inclinations.
[119] Regulation of the militia was codified by the
Second Continental Congress with the
Articles of Confederation. The revolutionaries also created a full-time regular army—the
Continental Army—but, because of manpower shortages, the militia provided short-term support to the regulars in the field throughout the war.
In colonial era Anglo-American usage, militia service was distinguished from military service in that the latter was normally a commitment for a fixed period of time of at least a year, for a
salary, whereas militia was only to meet a threat, or prepare to meet a threat, for periods of time expected to be short.
Militia persons were normally expected to provide their own weapons, equipment, or supplies, although they may later be compensated for losses or expenditures.
[120] A related concept is the
jury, which can be regarded as a specialized form of militia convened to render a verdict in a court proceeding (known as a petit jury or
trial jury) or to investigate a public matter and render a presentment or indictment (
grand jury).
[121]
...
Red Highlight mine
...
The first legislation on the subject was the
Militia Act of 1792 which provided, in part:
That each and every free able-bodied white male citizen of the respective States, resident therein, who is or shall be of age of eighteen years, and under the age of forty-five years (except as is herein after excepted) shall severally and respectively be enrolled in the militia,... every citizen, so enrolled and notified, shall, within six months thereafter, provide himself with a good musket or firelock.
Prior to the War of Independence, ...
...
en.wikipedia.org
~~~~~~~~~~~~~~~~
As we can see, in the times when the US Constitution was being written, most able bodied men were expected to be the militia and provide their own weapons/firearms.
As for "regulated", this pertains to Drill and Manual of Arms, etc., training in how to function as a group, rather than a mob.
...
Regulations for the Order and Discipline of the Troops of the United States was a drill manual written by Inspector General
Friedrich Wilhelm von Steuben during the
American Revolutionary War. Commissioned to train troops at
Valley Forge, Steuben first formed a model drill company of 100 men who were in turn to train further companies until the entire army was trained under the same procedures as the first company of troops. Following this exercise, Steuben published his drill instructions in a manual that was published in 1779 and widely distributed throughout the
Continental Army. This manual became commonly known as the army's "Blue Book". It remained the official U.S. military guide until 1812.
[1]
...
en.wikipedia.org
...
A
manual of arms was an instruction book for handling and using weapons in
formation, whether in the field or on
parade. Such manuals were especially important in the
matchlock and
flintlock eras, when loading and firing was a complex and lengthy process typically carried out in
close order. When capitalized, the term has reference to one of several important manuals, such as the
British Army manual of 1764, the manual of
Frederick the Great or
Von Steuben's
Regulations for the Order and Discipline of the Troops of the United States, adopted by the
Continental Army in 1777. The positions and evolutions contained in such manuals have become the standard for parade drill throughout most of the world.
...
en.wikipedia.org
~~~~~~~~~~~~~~
SO ... "well regulated" in context of 1770-1790s meant well trained (
Regulations for the Order and Discipline) in how to move as a formation and perform the same 'manual of arms' in regards to aiming, firing, and reloading firearms in a consistent, efficient, and standard manner. "By the ranks", Fire, than move to the rear to reload, then move forward to Fire again, etc.
As we also see, the militia was local men whom provided their own weapons and ammo, and were on call for immediate and emergency needs pending the arrival of 'regular' military~standing army formations/units.
The intent of the Founders in drafting the Second Amendment was to preserve the systems and structures in place prior to 1775 which the Colonists had used for local self-protection of homes and communities, as well as the foundation and basis for building the Continental Army used in the War of Independence. Also for later decades since the early USA had little sized "standing Army".