The constitution allows Congress to raise and support an army for no longer than two years, according to section 8. As opposed to the language of the next line which is to provide and maintain an provide for a navy.
The Continental Congress established the Continental Army in 1775 to fight the revolution. The Legion of the Unites States was established in 1792- 1796 to fight the Native Americans, which means it was established and renewed once.
The Congress re-raised the army for the war of 1812 and Mexican-American War from 1846-1848.
Once again for the Civil War Congress called up the state militias to form an army.
It was not until the late 19th / early 20th century that the current standing army was formed.
Taken from section 8 (Powers of Congress) of the United States Constitution.
To raise and support Armies, but no Appropriation of Money to that Use shall be for a longer Term than two Years;
To provide and maintain a Navy;
To make Rules for the Government and Regulation of the land and naval Forces;
To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;
To provide for organizing, arming, and disciplining, the Militia, and for governing such Part of them as may be employed in the Service of the United States, reserving to the States respectively, the Appointment of the Officers, and the Authority of training the Militia according to the discipline prescribed by Congress.
So you see, back in the day, there was no standing full time military force. A well regulated militia was necessary for the defense of the United State. There is a full time standing military today. The military IS the well regulated militia. The militia is no longer the "people".
A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.
The right to bear arms was because the "people" were the militia, the military. The full time standing military today is the well regulated militia. They keep and bare arms. The people should not keep and bare arms, they are not the militia anymore and it's not necessary for the security of the sate. The military is what's necessary for the security of the state. There's no way you could manage and regulate everybody now who has a gun. For god sake we don't even do back ground checks on half the people who buy guns. That's NOT WELL REGULATED.