Amendment II
The Second Amendment 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.
Resources
Below are some very good articles pertaining to The Second Amendment to better help to understand why it was included in the Bill of Rights and why it is so important.
The Second Amendment Is Our First Line of Defense – Alyssa Ahlgren
District of Columbia vs Heller
Guarantees of the Right to Arms In State Constitutions
America’s Founding Fathers On The Individual Right To Keep And Bear Arms
The Second Amendment and The Personal Right to Arms – Duke Law Journal
A Critical Guide to the Second Amendment