Well, in the constitution, (which our gov. founders cerated) it states that their roles are to “form a more perfect union, establish Justice, insure domestic Tranquillity, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity.” So, in my opinion, those are the most important roles. I hope this helped, and if so, please mark as brainliest, thanks ((: