Delaware became the first state to ratify the U.S. Constitution and join the Union on December 7, 1787. Delaware’s first two senators, George Read and Richard Bassett, took office on March 4, 1789. Delaware’s longest-serving senators include William Roth (1971–2001) and Joseph Biden (1973–2009). Among those who rose to leadership positions are Thomas F. Bayard, Sr., and Willard Saulsbury, Jr., both of whom served as the Senate’s president pro tempore, and Joe Biden, who served as vice president—the Senate’s constitutional president or presiding officer.