CNN  — 

Patrick Leahy, a Vermont Democrat and the longest serving US senator still in office, announced Monday he won’t seek reelection for a ninth term next year, after serving in the chamber since 1975.

“While I will continue to serve Vermont, Marcelle and I have reached a conclusion: it is time to put down the gavel,” said Leahy, referring to his wife. “It is time to pass the torch to the next Vermonter, who’ll carry on this work for our great state. It’s time to come home.”

“I will not run for reelection,” he added.

Leahy made his announcement at the Vermont State House, where he announced his first Senate campaign in 1974.

Leahy, 81, is the fourth longest serving senator in US history. As Senate president pro tempore, he is currently third in the line of presidential succession, following the vice president and speaker of the House.

Leahy was the first and remains the only Democrat to represent his home state in the US Senate, though his fellow US senator for the state is Bernie Sanders, an independent who caucuses with the Democrats.

Democrats have an extremely narrow margin for control of the Senate, and Republicans need to gain only one seat in next year’s midterms to regain control of the chamber. Republicans have in recent years won statewide office, including the state’s current governor, Phil Scott. However, Joe Biden won almost two-thirds of the vote there in 2020.

Scott’s press secretary Jason Maulucci told CNN, “Governor Scott has been clear that he is not running for the U.S. Senate next year. That has not changed.”

Democratic Rep. Peter Welch, Vermont’s at-large member of the House, issued a statement on the retirement, writing, “No one has served Vermont so faithfully, so constantly, so honestly, and so fiercely as Patrick.”

Leahy is the sixth senator and first Democrat to announce they won’t be seeking another term. Overall, Republicans will be defending 20 Senate seats and Democrats will be defending 14 in 2022.

In his speech on Monday, Leahy touted the deeds of his long career, establishing national standards for foods labeled “organic,” efforts to ban the export of land mines, confirming liberal judges, and sending billions to his small home state, including to address the coronavirus pandemic.

He also spoke about his work to provide healthy school lunches and create nutrition programs for infants and children, as well as ensuring the conservation of thousands of acres of farm and forest land in his state and across the US.

One of Leahy’s most historic roles came earlier this year as he presided over former President Donald Trump’s second impeachment trial in lieu of Chief Justice John Roberts, who chose not to oversee the proceedings because Trump was no longer in office.

Born in Montpelier, Vermont, on March 31, 1940, Leahy graduated from Saint Michael’s College in 1961 and Georgetown University Law Center in 1964. He was elected to the Senate just 10 years after that, making him the youngest US senator ever elected from Vermont. 

Prior to his time in Congress, he served as a state’s attorney in Vermont from 1966-1974.

This year Leahy also became chairman of the prestigious Appropriations Committee. He’s previously chaired the Judiciary Committee and oversaw the confirmations of justices Sonia Sotomayor and Elena Kagan. Leahy also led the Agriculture Committee in the late 80s and early 90s.

This story has been updated with additional developments Monday.

CNN’s Paul LeBlanc and Ethan Cohen contributed to this report.