[LexBaird]

I disagree with that, I see nothing in the wording of the Constitution or the BOR that states that Congress can place constraints on what a militia is.

Actually there is.

Article I, Sec 8: "The Congress shall have Power...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;"

It would seem that if they have the power to organize, arm and discipline the Militia, they have the power to define what it is.

[looscnnn]

I don't read that as placing constraints on what a militia is. I read that as Congress can call them into service of the US (provide for organizing), arm them, discipline the militia and have rule (govern) over only those that are in the service of the US government. That does not define them nor does it provide for defining what a militia is.