As of February 11, 2009, a total of 240 persons have served for 30 years or more in the United States Congress as Representative or Senator. That number is only 2% of the 11,893 men and women who have represented their states and congressional districts since the First Congress convened on March 4, 1789. Of the 240 Members serving 30 years or more, 139 served only in the House of Representatives; 29 served only in the Senate; and 72 served in both chambers. Four of the 240 Members are women, three of whom have served in the House and Senate. Over time, the number of Members serving 30 years or more has grown. Only two Members with over 30 years of service began serving in Congress in the 18 th century: Nathaniel Macon began his service in 1791; Samuel Smith, in 1793. Seven served entirely during the 19 th century. By 1967 (90 th Congress), a total of 100 Members had served 30 years or more. As of February 11, 2009, (111 th Congress) that number had risen to 240. Among Members of the 111 th Congress, 16 incumbent Senators and 18 incumbent Representatives have served 30 years or longer. Table 1 lists Members who have served 30 years or longer in descending order of the length of their congressional service, as measured in days. For each Member, the table presents the Member's party and state represented; dates of the Member's first and last day of service, by chamber; days of service in each chamber; and total days of congressional service. Total service is also presented in years and fractions of years. Calculations of days of service varied according to the pattern of a Member's service. For example-- Clarence A. Cannon of Missouri served in one continuous period from 3/4/1923 through 5/12/1964. The elapsed time from one date to the other was 15,045, but because Representative Cannon served for each of the elapsed days and on the first day, we add one day to the elapsed time for a total of 15,046 days. Justin Morrill served in both the House and the Senate, continuously from 3/4/1855 to 3/3/1867 in the House (4,383 days) and from 3/4/1867 to 12/28/1898 in the Senate (11,623 days). Morrill's total congressional service was the sum of those two periods, 16,006 days. Henry Jackson of Washington also served continuously in both the House and the Senate, but because of a statutory change there is an overlap of one day in his official dates of service. Jackson served in the House from 1/3/1941 through 1/3/1953, but his first day in the Senate was also on 1/3/1953. If we simply added his House service (4,384 days) and his Senate service (11,199 days), we would double-count 1/3/1953; so we add the days of service in each chamber (15,583 days) and subtract one day from that sum for Jackson's total days of congressional service (15,582 days). Alternately, we could simply count the days from when his House service started through the date of the day when his Senate service ended. Samuel Smith served in the House, then in the Senate, then again in the House, and then once again in the Senate. His first period of service (in the House) did not overlap with the second (in the Senate). There was a break between his first period of Senate service and his second period of House service, but there is an overlapping day (12/17/1822) when he moved finally from the House again to the Senate. Accordingly, we add the days of each period of service and subtract one day from the sum for a total of 14,276 days of congressional service. Table 1 draws the dates of congressional service from the Biographical Directory of the United States Congress, 1774-Present ; the "Table of United States Senators" in U.S. Congress, Senate, Senate Manual , S. Doc. 104-1; and various editions of the Congressional Directory (Washington: GPO). When a date in the Biographical Directory was unclear, CRS consulted other sources for clarification, as shown in notes to Table 1 .

Summary:
This report identifies the 240 Members of Congress who have served in Congress for at least 30 years, as of February 11, 2009. Those 240 Members are only 2% of the 11,893 individuals who have represented their states and congressional districts in Congress since 1789. Of the 240 Members with at least 30 years of congressional service, 139 have spent all of their congressional careers in the House; 29 have spent all of their careers in the Senate; and 72 have had combined service in the House and Senate. Among Members of the 111th Congress, 16 Senators and 18 Representatives have served 30 years or more. This report supercedes CRS Report RL30370, by [author name scrubbed], Specialist in American National Government. This report will not be updated.