President pro tempore of the United States Senate
Probably the most famous presidents pro tempore were John Langdon (first in this office), David Rice Atchison (D-MO), Benjamin Wade (R-OH), Arthur Vandenberg (R-MI), Carl Hayden (D-AZ) Richard Russell, Jr. (D-GA), Strom Thurmond (R-SC), Robert Byrd (D-WV), Daniel Inouye (D-HI), Orrin Hatch (R-UT), Chuck Grassley (R-IA) and Patrick Leahy (D-VT).