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 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; 
Constitution for the United States of America, Article I, Section 8, clause [xx]
The most significant of the above clauses to the Constitution is number 12. To understand exactly what was intended, it is necessary to understand what circumstances existed during the eighteenth century.
In 1768, when the number of British soldiers was being increased in Boston, the ministry send a reminder along with them that they could not be called out against a mob except on the authority of a civil officer. It was also understood that no soldier could fire upon a civilian, however severe the provocation. This could only be done under order from an officer, who in turn had to have written orders from a civil authority. There was no police force, and a sheriff or constable or magistrate could only deputize members of the posse comitatus to assist them, not to act on their behalf.
On March 5, 1770, an incident between British soldiers and colonists occurred which would become known as "the Boston Massacre". Shortly after the shooting Lieutenant Governor Hutchinson took a party to investigate the incident. Hutchinson, addressing Captain Preston, who was in charge of the soldiers involved in the shooting, asked, "How came you to fire without orders from a civil magistrate?" Preston replied, "I was obliged to, to save my sentry." Isaac Pierce, a member of Hutchinsonís party, interjected, "Then you have murdered three or four men to save your sentry!"
Perhaps, from this exchange we can more clearly see the conditions that existed two hundred years ago which would cause the Founders to provide a safeguard against a "standing army."
Going a bit further, we can look to December, 1772, when many leaders had called for an observance of the Boston Massacre. John Warren, Chairman of the Boston Committee of Safety, was among the speakers. He laid a foundation for the principles that would prevail in the creation of the Constitution some seventeen years latter when he described the events as an inevitable outcome of mistaken policy. He stated that when it was "found that ... taxation could not be supported by reason and argument, it seemed necessary that one act of oppression should be enforced by another, and therefore, contrary to our rights as possessing, or at least having just a title to possess, all the liberties and immunities of British subjects, a standing army was established among us in time of peace; and evidently for the purpose of effecting that, which it was one principal design of the founders of the constitution to prevent [referring to the English constitution which declared that a standing army in peacetime was against the law], namely, for the enforcement of obedience to acts which, upon fair examination, appeared to be unjust and unconstitutional." He want on to include that soldiers were "ever to be dreaded as the ready engines of tyranny and oppression."
Now the picture begins to brighten -- The original source of "tyranny and oppression" was the taxation "unjust and unconstitutional" This means that the acts were inconsistent with the concepts of the English constitution (although never written, principles have been "adopted" to what constitutes an oral constitution since the time of the Magna Carta).
Letís just suppose that an agency of government were to be assigned the responsibility of collecting a tax on an entity that was protected by the Constitution, say, (firearms, or property (in the form of income tax). Letís then suppose that this agency was given guns and other military equipment with which to enforce the collection of the taxes. Letís go a bit further and ask what would happen if this "standing army" were allowed to parade around without uniforms (are black ski masks and other items of clothing uniforms?). Finally, rather than them being subordinate to a magistrate, or other civil authority, let us put them directly under the supervision of one of their own, such as were Captain Preston of the British guard and Lieutenant Called of Mai Lai. (Preston and Calley were tried for their crimes, along with some of their men, and convictions were had)
As the picture brightens, perhaps another lamp should be cast into the arena to lighten the subject even more. We can only wonder exactly how the Founders would have reacted to seeing a "police force" of virtually hundreds of thousands of armed and uniformed (and some secret spy types) policemen, especially when we understand that the first "police force" in the world was instituted in London in 1829. The first such creature in this country was instituted in New York in 1844. Would the Founders have balked at allowing such a monster, one that epitomizes the events that so concerned them in the events discussed above? Would their concern over the implications of such a readily available source of force, intimidation and death have caused them to put additional limitations on government had they had any idea that such a monster as an army assigned the title of "police", without the separation of authority so obvious to their way of thinking? Might they be even more concerned over the sinister and potentially threatening concept of allowing them to act under the guise of having its their own built in "civil authority"? What if they were only subject to their own review for their possible misdeed"s rather than to a true civil magistrate or a criminal trial by jury?
It doesnít take much, once history is presented in a more proper form than our school system allows, to understand that local police department (let alone the national police under any guise) is as un-American as a slave labor camp (which is what many of our prisons are now becoming)?
The insidious encroachments onto our once sacred Constitution provides serious cause for alarm at the course the country is now set upon. Through slow and deceitful means the yoke of British tyranny has once again begun to strangle the wealth prosperity of the "American colonies". Once again the task is put before us to either cast out the oppression, and the oppressors, or bear the burden of subjugation, slavery and servitude both for ourselves and our posterity.
The choice is clearly ours -- and the time is clearly NOW! The expansion of this "police state" is nearly total and has already cost the lives hundreds and the property of tens of thousands, and the beast continues to grow. Is it our Right? Is it our Duty? to deal with this problem in the only way it can be dealt with? If so, let the process begin.