Final answer:
Historically, the term militia referred to white males of military age, and in Illinois, all men were considered part of the state militia. The right to keep and bear arms was a common-law right, and states relied on citizens for defense.
Step-by-step explanation:
Before the Civil War, in many states, the term militia typically referred to white males of military age. These individuals were liable to be called for service, and their right "to keep and bear arms" was a common-law right inherited from English law. This historical context can help us understand that all men living in Illinois were considered part of the state militia. Therefore, the answer to the question is 'a. Men'. This reflects an era where states expected certain members of society to be prepared and available for military service and to maintain their own arms, especially in anticipation of potential rebellions or invasions.The right to keep and bear arms was also considered a common-law right inherited from English law that predated the federal and state constitutions. The Constitution was not seen as a limitation on state power, and since the states expected all able-bodied free men to keep arms, gun control at that time focused on preventing enslaved people and their abolitionist allies from having guns.