Almost six decades and eleven presidents later, Democrat John Dingell reached a new milestone in the U.S. House this week, becoming the longest serving member of Congress ever.

As of Friday, Dingell had served 20,997 days (or 57 years, 5 months and 26 days) as a representative from southeast Michigan. He first joined Congress in 1955. He had already broken the record for the longest time served in the House of Representatives in February 2009. Now he has broken the overall Congressional record, previously held by Robert Byrd of West Virginia, who served in the House of Representatives from 1953 to 1959 and in the Senate from 1959 until his death on June 28, 2010.

But Dingell’s official time in the House doesn’t begin to tell just how long the 86-year-old Democrat has been a part of the lower house.

He first stepped foot on the House floor at age 6, when his father, John Dingell Sr. was first elected during the Great Depression in 1933. Dingell Jr. later served as House page during World War II, and was elected to his father’s seat at the age of 29 after Dingell Sr. died.

In the coming decades, Dingell rose to prominence in the House as chairman of the Energy and Commerce Committee. His career has seen him play a role in significant political fights over health care, civil rights and energy policy. Although he played key roles in the passage of Medicare in 1965 and the Clean Air Act Amendments of 1977, he has said that the vote of which he is most proud was for the Civil Rights Act of 1964.

Despite the House’s regard for seniority, Dingell eventually lost his grip on the energy committee in 2008. The changing of the guard was attributed to his Democratic colleagues belief that Dingell was not progressive enough on issues ranging from gun rights to climate change to fuel efficiency standards for cars.

-Noel Brinkerhoff, David Wallechinsky

To Learn More:

From ‘a Child of the House’ to Longest-Serving Member (by Ashley Parker, New York Times)

John Dingell: 'It Ain't How Long, It Is How Well' (by Emma Green, The Atlantic)

Rep. Ralph Hall becomes Oldest Person to Serve in House of Representatives (by Noel Brinkerhoff, AllGov)

John Dingell, the Congressman from General Motors (by Noel Brinkerhoff, AllGov)

Dingell to Set Record for House of Representatives Longevity (AllGov)