The Bill of Rights were written to protect the rights of the individual, why would the authors suddenly decide that only the 2nd amendment protected state's rights? The Federalists Papers provide insight to the thinking behind the authors, and the Supreme Court continually rules that the 2nd Amendment protects individual rights, not state militias.
Before the Revolutionary War began, the formal state militias were loyal to the crown. The American Revolutionary army was raised to fight the loyal Tory's and the British Regular Soldiers. The American militia were all the non-Tory, privately-armed citizens who maintained adequate arms and ammunition ("well-regulated" has been logically argued that it meant adequately-supplied in the vocabulary of the time) and able to respond to a call to arms on a minute's notice (hence the term Minutemen).
Before the Revolutionary War began, the formal state militias were loyal to the crown. The American Revolutionary army was raised to fight the loyal Tory's and the British Regular Soldiers. The American militia were all the non-Tory, privately-armed citizens who maintained adequate arms and ammunition ("well-regulated" has been logically argued that it meant adequately-supplied in the vocabulary of the time) and able to respond to a call to arms on a minute's notice (hence the term Minutemen).