What was the pourpose of the declaration of independence

The introductory sentence states the Declaration's main purpose, to explain the colonists' right to revolution. In other words, “to declare the causes which impel them to the separation.” Congress had to prove the legitimacy of its cause. It had just defied the most powerful nation on Earth.

the monroe doctrine is the best known u.s. policy toward the western hemisphere. buried in a routine annual message delivered to congress by president james monroe in december 1823, the doctrine warns european nations that the united states would not tolerate further colonization or puppet monarchs.