Final answer:
The Second Amendment to the United States Constitution, which mentions a 'well regulated militia' and guarantees the right to bear arms, has been interpreted to also confer the right to self-defense, per the Supreme Court rulings in District of Columbia v. Heller and McDonald v. Chicago.
Step-by-step explanation:
The amendment in question, which mentions a "well regulated militia" and has been interpreted to confer the right to self-defense as well as the right to bear arms, is the Second Amendment to the United States Constitution. The Supreme Court's majority opinion in the 2008 case District of Columbia v. Heller ruled that the Second Amendment protected an individual's right to possess a firearm for self-defense.
This interpretation was later applied at a state level in the 2010 case McDonald v. Chicago. Furthermore, the case U.S. v. Cruikshank in 1875 focused on this same amendment. The Supreme Court noted, regarding this amendment, that the prefatory clause does not limit the operative clause grammatically but rather announces a purpose.
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