Last Monday, after 20 years as Congresswoman for the Sixth Congressional District, Lynn Woolsey announced her retirement before a crowd of family, friends and press in the backyard of her Petaluma home. "Twenty years. And I'm going to be 75 years old," said Woolsey. "It makes sense to me that it's time."

Woolsey's legacy will be a considerable one. First elected in 1992 during an election cycle dubbed "year of the woman," Woolsey once described herself as "the first welfare mother to serve in Congress." Hers has been a long career of voting against war and war funding, most notably in her 2002 stand against the invasion of Iraq.

"Nothing animated me more than opposition to the war," said Woolsey during her retirement speech, calling the Iraq War a "moral blight."

As co-chair of the Congressional Progressive Caucus, Woolsey has also used her time on Capitol Hill to advocate for the unemployed, children and women. Opposed to a barrage of proposals challenging women's reproductive freedom, she advocated strongly for women's right to safe and legal abortion. Congresswoman Barbara Lee of Oakland, who introduced Woolsey on Monday, called her a "leader in women's rights."

In 2009, Woolsey spoke against President Obama's extension of tax breaks for the wealthy. "If we got rid of tax breaks for millionaires and billionaires for one measly week," Woolsey said from the Senate floor, "we would pay for the entire [Women, Infants and Children] program for a year."

More recently, Woolsey fasted for a day as part of a protest against GOP budget cuts agreed to by Obama. At the beginning of June, she came under fire from the National Jewish Democratic Council for her remarks at a San Rafael peace rally where she praised a Jewish-American Code Pink activist who disrupted Israeli prime minister Benjamin Netanyahu's speech to Congress. At the same rally, writer and activist Norman Solomon paraphrased Martin Luther King Jr., calling Woolsey a "drum major" for peace.

"She has spoken out against war when it was unpopular to do so, and she did it hundreds of times, literally, going to the house floor and speaking," says Solomon by phone. "She is a role model, someone who has spoken for peace and social justice without asking which way the wind is blowing. What she has continued to give to our district and to the country is very inspiring."

California State Assembly member Jared Huffman, who represents Marin and parts of Sonoma County, says that Woolsey will be remembered for her "steadfast advocacy for peace" and her love for her district. "It crossed party lines," says Huffman by phone. "I know conservative Republican ranchers who love Lynn Woolsey."

Both Solomon and Huffman have been marked as front-runners for Woolsey's open Congressional seat in solidly democratic territory. Third-term Marin County supervisor Susan Adams has also filed paperwork to form a congressional campaign. "I'm actively working on it," says Adams, a nurse practitioner and educator, by phone. "I'm putting together a team to see what my chances are."

Huffman plans to make an official announcement regarding campaign contributions and goals on July 15, but says he is "hitting targets and actually exceeding them."

"We haven't seen an open congressional run in 20 years. It's going to be expensive. It's going to be hard-fought, there's no doubt about that," says Huffman. "I'm certainly working hard to put myself in the strongest possible position to make that run when the time comes."

Solomon has wasted no time jumping into a campaign he's christened "grassroots versus Astroturf."

"Will we have an independent Democrat who is willing to speak truth to power and about power in Washington," says Solomon, "or will we have a sort of party functionary who goes along with the top of the party hierarchy?"

Woolsey has not endorsed any of the possible Democratic candidates.

Woolsey said Monday that she wanted to "learn how to sit" and that her role as the president of Americans for Democratic Action will be a post-retirement platform for peace.

"We have to continue to speak up—and we will, because we still have 100,000 men and women in harm's way in Afghanistan," said Woolsey. "Most of all, we must never give up. We must, without hesitation or apology, fight for what we know is right."