Everything we need to knwo about the U.S. gov. is in the Constitution, and they are "to form a more perfect union", "to establish justice", "to insure domestic trnaquility", "to provide for the common defense", "to promote the general welfare", and "to secure the blessings of Liberty". I believe these are the most important roles of our government. I hope you found this answer helpful, and, if so, please mark as brainliest, thank you! XD
