"Except for the title 'father,' there is no title, including 'vice president,' that I am more proud to wear than that of United States senator," Biden said in his farewell address to his colleagues.
The U.S. Senate is "an incredible place," he said, where personal relationships can unlock "true potential."
"Every good thing I have seen happen here, every bold step taken in the 36-plus years I have been here," Biden said, "came not from the application of pressure by interest groups, but through the maturation of personal relationships."
Biden thanked the people of Delaware, former and current Senate staff, his family and fellow senators "for making my Senate service possible and this next chapter in my career and life so hopeful."
Biden noted the Senate hasn't seen the last of him because as vice president, he would preside over the body and cast tie-breaking votes.
"I say for the last time," Biden said in closing, "and with confidence in all of you, optimism in our future, and a heart with more gratitude than I can express: I yield the floor."