What is the name of the system that keeps one branch of the federal government?

What british document established the right of free speech that was reinforced by this excerpt

As with any small island country, cuba has fewer natural resources than countries such as brazil. this affects their economy in that cuba a) exports only manufactured products. b) exports more products than it imports.. c) must import more products than it exports. d) has imposed trade barriers against the united states.

Newspaper started by john campbell: