It is your first right that you can use to stand with other Americans to protect your rights, freedoms and defend the Constitution.
Well, the first right specifically mentioned in the Constitution is freedom of religion. Since I'm an atheist, that one doesn't really mean much to me but I do support it. Other than that, I have no idea what you are talking about.
Most Americans think that the First Amendment of the 1792 Bill of Rights is the first constitutional right they can use and interact under. The first one chronologically is the right to "alter or abolish" from the Declaration of Independence of 1776, but that is codified in Article 5 of the 1787 constitution. Freedom of speech is needed by the people for the creation of unity needed to use the right to "alter or abolish" as the people must unify in their states.