List of longest-serving members of the United States Congress


This list of members of the United States Congress by longevity of service includes representatives and senators who have served for at least 36 years, in the United States Senate, the United States House of Representatives, or both. In cases where there is a tie in time, the following criteria will sort people higher:
  1. Achieved time uninterrupted
  2. Achieved time first
  3. Senators over representatives
  4. Senate and House seniority

U.S. Senate time

The 90th Congress was notable because for a period of 10 days, it contained within the Senate, all 10 of what was at one point the top 10 longest-serving senators in history until January 7, 2013, when Patrick Leahy surpassed Russell B. Long as the 10th longest-serving senator in history. This short 10-day period stretched from the appointment of Ted Stevens of Alaska to fill a vacancy, to the retirement of Carl Hayden of Arizona early the next year. The 107th Congress was the most recent one to contain the top 7 longest serving senators in history.
The 99th Congress and the 100th Congress were the periods in which most people from this list were serving together.