The Second Amendment of the United States Constitution reads: "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
The founding fathers added this amendment to the United States Constitution to give the people of the United States our 2nd amendment rights. This right protects our country from foreign and domestic threats and enemies. So the citizens of our country which together are supposed to govern our country can defend it from powers that try and take that governing ability away from "We The People".