Rep. Jim Sensenbrenner at a town hall in 2017.
PHOTO: WDJT
Rep. Jim Sensenbrenner at a town hall in 2017.
(CNN) —  

Wisconsin Rep. Jim Sensenbrenner, a Republican who is the second-most senior member of the House, announced on Wednesday that he will not seek reelection in 2020.

Sensenbrenner said he will retire in January 2021, at the end of his current term.

He will become the longest-serving Wisconsin congressman in the state’s history late next year when he reaches 42 years of service, overcoming former Democratic Rep. David Obey’s record of 41 years, nine months and three days.

He is the 13th Republican lawmaker to announce their plans for departure in recent weeks, adding to a growing list of House GOP retirements.

Before running for the House, Sensenbrenner, a Republican stalwart, served in the Wisconsin state legislature for 10 years.

“When I began my public service in 1968, I said I would know when it was time to step back. After careful consideration, I have determined at the completion of this term, my 21st term in Congress, it will be that time,” Sensenbrenner said in a statement Wednesday evening.

The congressman previously chaired the House Judiciary Committee and the House Science Committee. He is known for introducing the USA Patriot Act in 2001.

“It has been my privilege to serve the people of Southeast Wisconsin and I have found true fulfillment in all the challenges and many accomplishments that have peppered my long career,” Sensenbrenner said. “It is rare when life presents the perfect opportunity to make an impact in a way that has been so meaningful. I am forever grateful.”

In 2018, Sensenbrenner comfortably won reelection in Wisconsin’s conservative 5th Congressional District with 62% of the vote.

Earlier on Wednesday, Texas Rep. Bill Flores said that he would not run for reelection. And on Friday, Illinois Rep. John Shimkus had revealed he would leave Congress as well, just a few days after Wisconsin Congressman Sean Duffy announced that he would resign in late September to spend time with his family ahead of the birth of his ninth child.

This story has been updated.