B. Military Service
Non-citizens have long enjoyed (or suffered, depending on how you look at it) the right of military service. During the Civil War, nearly twenty-five percent of the combatants were foreign-born. Pursuant to the Enrollment Act of March 3, 1863, men between the ages of twenty and forty-five “of foreign birth who shall have declared on oath their intention to become citizens” were subject to the draft. After the Civil War, non-citizen combatants were entitled to military pension benefits and appear to have sometimes received them even after having left the United States to return to their countries of origin. However, empirical research suggests that, as a practical matter, non-citizens had less access to pension benefits than citizens and were rewarded less on average than native recruits.
Non-citizens continued to be subject to conscription up until it was abolished in 1973, and to this day most non-citizens in the US (including undocumented aliens) must register for the selective service. Today non-citizens remain an important part of the United States' volunteer military, and there are special provisions of immigration law designed to facilitate citizenship for non-citizens who serve in the military.