MADISON, Wis. (AP) — Wisconsin state Sen. Fred Risser, the longest-serving legislator in the nation's history, said Thursday that he plans to retire.

Risser, 92, announced that he won't seek re-election this fall. The Democrat has represented Madison in the Wisconsin Legislature for 64 years. He's the last World War II veteran remaining in any of the state legislatures and Congress, according to his office.

Born in 1927, Risser was first elected to the Wisconsin Assembly in 1956 and moved to the Senate in 1962. He served as Senate president 15 times over 25 years and worked with 13 different governors.

Risser has said one of his greatest legislative accomplishments was crafting a bill in 2009 that banned smoking in all workplaces. Two years later he was one of 14 minority Democrats in the Senate who fled the state in a futile attempt to prevent a vote on then-Republican Gov. Scott Walker's contentious plan to strip public workers of their union rights.

Though never a flashy orator, Risser was a constant presence in the Capitol, strolling the halls in his red beret and this past year with a pair of walking sticks. But as an expert in parliamentary procedure, he would often stand and lecture Republicans on proper Senate protocols, even when he was in the minority party.

He told The Associated Press in 2007 that serving in the Legislature could be frustrating but the job gave him an adrenaline rush.

“There’s nothing more fascinating than dealing with human beings,” he said. “It keeps you energized.”

Risser served as a Navy medic in Panama during World War II, then earned his bachelor and law degrees from the University of Oregon in the early 1950s. He and his wife, Nancy, have three children.

When he jumped into public service, he became the fourth generation of his family to represent Madison in the Legislature. His great-grandfather was a Unionist following the Civil War, his grandfather was a Republican and his father was a Progressive. The Wisconsin Department of Justice’s headquarters is named the Risser Justice Center to honor the family.

His legislative district included the core of Madison, the most liberal city in the state that includes the University of Wisconsin-Madison and the largest number of state employees in Wisconsin.

In an interview with the National Conference of State Legislatures in 2009, Risser lamented how divisive politics had become and the cost of campaigns.

“The worst part is the excessive partisanship that I believe has trickled down from Washington, D.C.,” he said. “Also the cost of running for the Legislature has gotten way too expensive. We have some races in Wisconsin that run into the millions of dollars. I believe this discourages a lot of good people from running for office.”

Risser said he had thought about running for higher office but the timing was never right and the opportunity never presented itself. But he said he was happy with how his career turned out.

State Rep. Chris Taylor, a Madison Democrat, issued a statement moments after Risser also announced his retirement that she would not seek re-election to the Assembly or any other legislative seat.