The militias because of the uncertainty of the times, their status was not clearly defined at times. The colonies had militias before the Revolutionary war and they served britain in the French and Indian Wars. They were part-time soldiers raised by the local colony. In the Revolutionary War, necessity was the great motive behind them. The need to protect remote areas from indians and the war with England that required troops caused militias to be raised. Since most of them were sponsored by state governments, few were raised by the continental congress. They were equipped with older arms while the cannon tended to similiar to those the regular army had. They contributed much to the success of the american arms in the war with many of these men going into the regular army. They protected the back areas and relieved the regulars for deployment elsewhere. There may have been some artillery pieces privately owned but this was not the practise. Artillery units tended to be regulars while their property and guns belonged tothe governments.
The right to bear arms is still debated today. Does it mean private arms or arms controlled by the government?