Rep. Dennis Hastert announced Friday he will not seek re-election next year, ending what will be a 22-year run in Congress that at its pinnacle made him the most powerful member of the House of Representatives and next in line to succeed the president behind the vice president.

"After all these years, it only seems fitting to reunite here in this place as I announce my future plans. And as some have now speculated, after much consideration I have decided not to seek another term in Congress," the Illinois Republican told the audience gathered at the Kendall County courthouse in Yorkville, Ill.

Hastert's remarks were interrupted several times by applause, but maybe the heaviest shouts of approval came when he made reference to his humble beginnings.

"Who would have guessed that a wrestling coach from Kendall County in Illinois would be the longest-serving Republican speaker of the House of Representatives?" he asked to a loud roar.

Last week, Hastert sent out a letter to supporters amid some secrecy, setting a date and time for an announcement, but the subject of the announcement wasn't clear, only that it was "an important announcement regarding my future."

As news of the announcement surfaced, most expected that the subject was about his campaign intentions — and most believed that he would announce his retirement after he served his term.

Officially, his staff didn't reveal his intentions, but congressional aides confirmed to FOX News and several other sources this week that Hastert would not seek re-election. And in media interviews late Thursday and early Friday, Hastert confirmed as much.

Leading up to the announcement Friday, light jazz played over the speaker system. When Hastert took the podium, he stood in front of the courthouse in the town where he used to coach high school wrestling, backed by his wife, Jean, and other family members. Loud applause erupted as he addressed a group gathered on a warm summer morning, some holding Hastert campaign posters.

Hastert pointed to local achievements as well as national ones -- like allowing seniors to work while receiving Social Security, allowing for health savings accounts and passing the Medicare prescription drug program.

"We repealed the death tax. We delivered the two largest tax cuts in American history, because we trusted people to make their own decisions with their own money," Hastert said, adding that while those programs fuel the U.S. economy, "our critics just didn't get it, and frankly, they still don't."

Hastert said the most important legislation passed under his tenure were national and homeland security-related laws following the Sept. 11, 2001, attacks.

"On that dark day, for our nation, congressional leaders vowed to do whatever was necessary to protect our citizens from future attacks. And that is exactly what we did," Hastert said, pointing to intelligence-sharing measures taken.

"Beyond our borders, we made good on our promise to identify and eliminate those targeting the United States, wherever they reside. And Americans can disagree about national defense strategy, but there is no arguing that we led Congress to taking critical steps that have kept our citizens safe from attack," Hastert said.

After finishing his brief remarks, Hastert waded through the crowd packed with media and friends, hugging them and shaking their hands.

Hastert became speaker in 1999, succeeding Republican Newt Gingrich. Hastert went on to be the longest-serving Republican speaker of the House. He was succeeded this year by Rep. Nancy Pelosi, D-Calif., after Republicans lost control of the House in last November's elections.

The Republican majority in Congress was threatened heading into last year's elections with a number of congressional ethics investigations coming to a head, as well as public opinion over the GOP-led White House and Congress' administration over the Iraq war.

When the dust settled, Republicans had lost 30 seats in the House, and Hastert pulled himself out of the running for Republican leadership positions for the new Congress.

Speaking to reporters shortly after the event Friday, Hastert indicated he would serve out the rest of his term, saying he's going to "continue to serve as long as I feel I can be effective in the Congress, and that's what my intent was."

He declined to say if he planned to back any candidate.

"I have to wait to see who files," he said.

He also said he's not sure what he'll do next, adding that it would not be proper for him to arrange something until he has left the House.

In a lighter question about his thinner appearance, he admitted: "I've lost a couple pounds. ... I eat about a third of what I ate before, and I try to stay at it."

Some of Hastert's most powerful friends issued statements after his announcement, praising him as a person and his stewardship over Congress.

"He is a good and decent man, and he was a strong and effective speaker," President Bush said. "During his two decades in Congress, Denny rose through the ranks as a hard-working member whom colleagues on both sides came to admire, trust, and respect ... As my good friend prepares to move on to the next phase of his life, he has my gratitude for his distinguished service."

House Minority Leader John Boehner saluted Hastert for his continued fight for the party agenda, including fighting Democratic energy proposals and boosting domestic energy sources.

"Now, even after his tenure as speaker, his days of effective legislating continue. I look forward to serving beside him for the next year and a half, and I am eager to serve beside his Republican successor in the years to come. In the meantime, I wish Denny and Jean all the best as they prepare for the next stage of their lives," Boehner said.