Updated

Nearly a month after he announced plans to leave Congress due to sexual misconduct allegations that began in November, Sen. Al Franken officially resigned on Jan. 2.

Aides to the senator told Fox News that Franken has provided his letter of resignation to Minnesota Gov. Mark Dayton.

Franken will be replaced by Lt. Gov Tina Smith, who is expected to be sworn in on Wednesday morning.

Franken, who has been in office since 2009, was plagued by multiple accusations of sexual misconduct and faced a Senate Ethics Committee investigation. The allegations began after Los Angeles radio anchor Leeann Tweeden accused him of forcibly kissing her during a 2006 USO tour.

Dozens of his Democratic colleagues called for him to step aside after the allegations came to light. 

Below is a timeline of key moments in the senator’s political career.

Prior to 2008

Before running for Senate, Franken was a comedy writer, actor, author and radio talk show host for 37 years, according to his Senate website. Franken’s comedy career included time as a writer and performer for NBC’s “Saturday Night Live.”

2008

After being tapped by the Democratic-Farmer-Labor Party in June of 2008, Franken was elected to represent Minnesota in the Senate later that year. After a protracted recount, his opponent, Republican Norm Coleman, finally conceded to Franken  -- officially ending one of the longest Senate races in U.S. history, Politico reported at the time.

AL FRANKEN DRAGS OUT SENATE DEPARTURE, ONLY MENTIONS 'TRANSITION' AFTER REPLACEMENT NAMED

2013

Franken was the primary sponsor behind a bill that allows the Fond du Lac Band of Lake Superior Chippewa in the State of Minnesota to lease or transfer certain land. The bill was enacted later that year.

2014

Franken was re-elected to his Senate seat in 2014, easily defeating his Republican challenger, Mike McFadden.

Later that year, Franken endorsed Democrat Hillary Clinton for president during an interview on MSNBC.

2015

Franken sponsored the Comprehensive Justice and Mental Health Act of 2015, which was enacted that same year. The law increases public safety by “facilitating collaboration among the criminal justice, juvenile justice, veterans treatment services, mental health treatment, and substance abuse system,” according to the bill.

2016

Franken visited nine different states in 2016 as part of an effort to help Clinton get elected to the White House. He traveled to New Hampshire, Wisconsin and California, where he campaigned and raised money for the Democratic presidential candidate.

Franken first met the Clintons in 1993. Hillary Clinton supported Franken in his 2008 run for Senate.

Also in 2016, Franken was the sponsor behind a bill called the Adding Zika Virus to the FDA Priority Review Voucher Program Act. The bill, which was later enacted into law, added the Zika virus to the list of tropical diseases under the priority review voucher program.

Jan. 2017

Franken questioned Betsy DeVos, President Trump’s pick for secretary of education, on several issues during her confirmation hearing. Franken later said that DeVos “failed to adequately answer even the most basic questions about education policy.”

Oct. 2017  

Franken and Attorney General Jeff Sessions got into a heated exchange during Sessions’ Senate Judiciary Committee hearing. Franken pressed Sessions about his meetings with Russian officials during the 2016 presidential campaign.

AL FRANKEN ACCUSED OF KISSING, GROPING LA TV HOST WITHOUT CONSENT

Nov. 16, 2017 

Radio personality Leeann Tweeden alleged in a post on the KABC website that Franken kissed and groped her without her consent during a USO tour in 2006. Tweeden said that Franken insisted on practicing a kiss for a skit.

“We did the line leading up to the kiss and then he came at me, put his hand on the back of my head, mashed his lips against mine and aggressively stuck his tongue in my mouth,” she said, adding that she pushed him away.

Tweeden said that in another incident, she fell asleep during a flight and later looked at a CD of photographs. Her post included an image of Franken with his hands over her chest.

“I couldn’t believe it,” she wrote. “He groped me, without my consent, while I was asleep.”

"I certainly don't remember the rehearsal for the skit in the same way, but I send my sincerest apologies to Leeann," Franken said in an initial statement. "As to the photo, it was clearly intended to be funny but wasn’t. I shouldn’t have done it.”

Franken apologized to Tweeden again in a longer, second statement. In it, he said that the photo was “completely inappropriate” and called for an ethics investigation.

Nov. 23, 2017

Franken apologized again, this time saying that he “crossed the line.”

“I’m a warm person; I hug people,” Franken said in a statement at the time. “I’ve learned from recent stories that in some of these encounters, I crossed a line for some women -- and I know that any number is too many.”

“I feel terribly that I've made some women feel badly,” he added, “and for that I am so sorry, and I want to make sure that never happens again.”

The statement came after he had been accused of groping by a total of four women.

Ultimately, eight women in all would accuse Franken of sexual misconduct.

Nov. 30, 2017

The Senate Ethics Committee said in a statement that it had "opened a preliminary inquiry into Senator Franken’s alleged misconduct."

Dec. 6, 2017

Multiple Democratic senators call for Franken to step down.

Dec. 7, 2017 

Franken said he would step down "in the coming weeks."

Dec. 13, 2017 

Minnesota's Lt. Gov. Tina Smith was appointed by Gov. Mark Dayton to replace Franken.

“Tina Smith will make an excellent United States Senator,” the outgoing senator said in a statement. Franken also said that he is looking foward “to working with her on ensuring a speedy and seamless transition.”

Dec. 20, 2017 

Fox News confirmed that Franken is going to resign Jan. 2.

Jan. 2, 2018

Franken formally hands in his letter of resignation to Minnesota Gov. Mark Dayton.

Fox News' Chad Pergram and The Associated Press contributed to this report.