I should add that as long as the "civic right" interpretation of the Second Amendment is out there, this is still a valid case. In fact, while the Heller-McDonald line of cases said this may no longer be applicable, the fact that the court said that "to drill or parade with arms, without, and independent of, an act of Congress or law of the State authorizing the same" would relate to public order means that this is a very relevant case to a world where people want to openly carry arms in public.
Herman Presser was part of a citizen militia group, the Lehr und Wehr Verein (Instruct and Defend Association), a group of armed ethnic German workers, associated with the Socialist Labor Party. The group had been formed to counter the armed private armies of companies in Chicago.
The indictment charged in substance that Presser, on September 24, 1879, in the county of Cook, in the State of Illinois, "did unlawfully belong to, and did parade and drill in the city of Chicago with an unauthorized body of men with arms, who had associated themselves together as a military company and organization, without having a license from the Governor, and not being a part of, or belonging to, 'the regular organized volunteer militia' of the State of Illinois, or the troops of the United States." A motion to quash the indictment was overruled. Presser then pleaded not guilty, and both parties having waived a jury the case was tried by the court, which found Presser guilty and sentenced him to pay a fine of $10.
In December 1879, marched at the head of said company, about four hundred in number, in the streets of the city of Chicago, he riding on horseback and in command; that the company was armed with rifles and Presser with a cavalry sword; that the company had no license from the governor of Illinois to drill or parade as a part of the militia of the State, and was not a part of the regular organized militia of the State, nor a part of troops of the United States, and had no organization under the militia law of the United States.Presser claimed the law violated his rights under the Second Amendment.
"Unless restrained by their own constitutions, state legislatures may enact statutes to control and regulate all organizations, drilling, and parading of military bodies and associations except those which are authorized by the militia laws of the United States."
The Presser Court said:
It is undoubtedly true that all citizens capable of bearing arms constitute the reserved military force or reserve militia of the United States as well as of the States, and in view of this prerogative of the general government, as well as of its general powers, the States cannot, even laying the constitutional provision in question out of view, prohibit the people from keeping and bearing arms, so as to deprive the United States of their rightful resource for maintaining the public security, and disable the people from performing their duty to the general government. But, as already stated, we think it clear that the sections under consideration do not have this effect.The Court emphatically disposed of Presser's argument that there exists a right to assemble, drill, or march in a militia independent of authorization by state or federal law:
The right voluntarily to associate together as a military company or organization or to drill or parade with arms, without, and independent of, an act of Congress or law of the State authorizing the same, is not an attribute of national citizenship. Military organization and military drill and parade under arms are subjects especially under the control of the government of every country. They cannot be claimed as a right independent of law. Under our political system they are subject to the regulation and control of the State and Federal governments, acting in due regard to their respective prerogatives and powers. The Constitution and laws of the United States will be searched in vain for any support to the view that these rights are privileges and immunities of citizens of the United States independent of some specific legislation on the subject.In other word, as I have been saying all along, you do not belong to a "Constitutional Militia" unless you belong to an actual serving organisation which is organised under Article I, Section 8, Clauses 15 & 16 of the United States Constitution. As per Article VI, Clause 2 of the United States Constitution, that body is the National Guard: whether you like it or not.
In fact, reading Presser, it's pretty clear that the "unorganised militia" argument is seriously nonsensical from a legal point standpoint. There is no basis for claiming that a reserve pool with no obligation of service (hence Unorganised, Sedentary, reserve, inactive, general or other term indicating INACTIVITY Militia) has any "right" to arms.
This is especially true if your unit was not created by act of congress and under some form of governmental control.
I would also add that local governments are probably on good ground in strictly regulating open carry rallies by combining this case with the comment in Heller that:
Like most rights, the right secured by the Second Amendment is not unlimited. From Blackstone through the 19th-century cases, commentators and courts routinely explained that the right was not a right to keep and carry any weapon whatsoever in any manner whatsoever and for whatever purpose. See, e.g., Sheldon, in 5 Blume 346; Rawle 123; Pomeroy 152–153; Abbott 333. For example, the majority of the 19th-century courts to consider the question held that prohibitions on carrying concealed weapons were lawful under the Second Amendment or state analogues. See, e.g., State v. Chandler, 5 La. Ann., at 489–490; Nunn v. State, 1 Ga., at 251; see generally 2 Kent *340, n. 2; The American Students’ Blackstone 84, n. 11 (G. Chase ed. 1884).Additionally, as I pointed out before the First Amendment protect peaceable assembly. Any armed group is not "peaceable" in any realistic sense of that word.