Columbia subject headings:
Firearms--Law and legislation--United States.
United States. Constitution. 2nd Amendment--History.
Harvard subject headings:
Constitutional amendments--United States
Constitutional history--United States
Firearms--Law and legislation--United States
United States--Militia--History.
United States. Constitution. 2nd Amendment
United States. Constitution. 2nd Amendment--History.
Princeton subject headings:
Firearms--Law and legislation--United States--History.
United States. Constitution. 2nd Amendment--History.