Original: A formative member of the Democratic-Republican Party with a political base in NY , Burr served in the New York State Assembly ( 1784 -- 1785 , 1798 1801 ) , as New York State Attorney General ( 1789 -- 1791 ) , United States Senator ( 1791 -- 1797 ) , and for one term as vice president under Jefferson .
Simplified: Burr served in the New York State Assembly , as New York State Attorney General , and as a United States Senator before serving as Vice President .