video at top: Barbara Mikulski (used in article #21149791)
Barbara Mikulski: A pint-sized trailblazer with a huge legacy
First elected to the House of Representatives in 1976 then the Senate in 1987, the 78-year-old veteran lawmaker is the longest serving woman in congressional history and at 4'11", she’s known as one of the fiercest fighters for women, families and the middle class.
WASHINGTON, DC - FEBRUARY 10: U.S. Sen. Elizabeth Warren (D-MA) (L) listens to Sen. Barbara Mikulski (D-MD) (R) during a hearing before Senate Health, Education, Labor and Pensions Committee February 10, 2015 on Capitol Hill in Washington, DC. The committee held a hearing on 'The Reemergence of Vaccine-Preventable Diseases: Exploring the Public Health Successes and Challenges.' (Photo by Alex Wong/Getty Images)
WASHINGTON, DC - NOVEMBER 13: U.S. Sen. Barbara Mikulski (D-MD) (C) shakes hands with Senator-elect Joni Ernst (R-IA) (L) as (2nd L-R) Sen. Jeanne Shaheen (D-NH), Sen. Kirsten Gillibrand (D-NY), Sen. Mazie Hirono (D-HI), Sen. Susan Collins (R-ME), Senator-elect Shelley Moore Capito (R-WV), and Sen. Amy Klobuchar (D-MN) look on during the Senate Women Power Workshop November 13, 2014 on Capitol Hill in Washington, DC. The traditional and bipartisan workshop was co-hosted by Sen. Mikulski and Sen. Collins. (Photo by Alex Wong/Getty Images)
WASHINGTON, DC - MARCH 12: U.S. First Lady Hillary Clinton(C) walks with Senators Carol Mosley Braun(L), Barbara Boxer(2nd-L), Barbara Mikulski(2nd-R) and Diane Feinstein(R) 11 March 1993 after a meeting with them and other women senators in the U.S. Capitol. (Photo credit should read ROBERT GIROUX/AFP/Getty Images)
WASHINGTON, DC - JUNE 18: Senators Edward Kennedy (D-MA) (R) and Barbara Mikulski (D-MD) (L) chat 18 June 1987, in Washington, DC. during a press conference where they and several other lawmakers talked about legislation that would cut off important economic subsidies to South Korea. Kennedy said, 'Now is the time for transation from dictatorship to democracy' and that if the South Korean government does not implement reforms, the Olympic Games in 1998 will be in jeopardy. (Photo credit should read RENATO RETOLO/AFP/Getty Images)
WASHINGTON, DC - APRIL 7: US Sen. Barbara Mikulski (R), D-Maryland, talks with Prime Minister of Pakistan Benizar Bhutto(L) during a visit with congressional leaders on Capitol Hill in Washington 07 April 1995. Bhutto is on a 10-day visit to the US and is scheduled to meet with President Bill Clinton 11 April. AFP PHOTO (Photo credit should read RICHARD ELLIS/AFP/Getty Images)
401916 04: Sen. Barbara Mikulski (D-MD) shows a book to actor Christopher Reeve March 5, 2002 prior to a hearing on 'The Dangers of Cloning and The Promise of Regenerative Medicine' before the Senate Committee on Health, Education, Labor and Pensions on Capitol Hill in Washington, DC. Reeve, who hopes human cloning research may one day help to heal the broken spine that confines him to a wheelchair. (Photo by Alex Wong/Getty Images)
WASHINGTON - JULY 31: Sen. Barbara Mikulski (C) (D-MD) praises Virginia firefighter Mike Staples (R) with Sen. Joe Lieberman (L) (D-CT) during a news conference to highlight the importance of protecting workers' rights in the new Homeland Security Department July 31, 2002 in Washington, DC. U.S. President George W. Bush has said that he wants wider powers to limit union membership for the 170,000 projected employees in the new department. Staples was on the scene as a rescue worker at the Pentagon after the September 11 attack. (Photo by Mike Theiler/Getty Images)
ROCKVILLE, MD - OCTOBER 9: U.S. Senator Barbara Mikulski (D-MD) (C) speaks as Senator Paul Sarbanes (D-MD) (L) and Montgomery County Executive Douglas Duncan (R) listen during a news briefing on the recent sniper shootings at the Montgomery County Police Headquarters October 9, 2002 in Rockville, Maryland. Mikulski and Sarbanes expressed their support to local law enforcement agencies on their efforts investigating the case. (Photo by Alex Wong/Getty Images)
WASHINGTON, D.C. - MAY 07: Actress Jessica Alba shakes hands with Sen. Barbara Mikulski (D-MD) after a meeting on children's healthcare reform at Capitol Hill on May 7, 2009 in Washington, D.C. (Photo by Kris Connor/Getty Images)
WASHINGTON, DC - FEBRUARY 24: Joined by fellow Senate Democrats, Appropriations Committee ranking member Sen. Barbara Mikulski (D-MD) (C) accuses Republican Senate leaders of manufacturing the possible shutdown of the Department of Homeland Security during a news conference at the U.S. Capitol February 24, 2015 in Washington, DC. Democrats have successfully blocked the $39.7 billion funding legislation because it would also strip away the executive actions in which President Barack Obama eased the deportation threat for several million undocumented immigrants. If Republicans and Democrats can not work around the impasse then 30,000 DHS employees will go home February 28 and 200,000 more will work without paychecks until a solution is found. (Photo by Chip Somodevilla/Getty Images)
First elected to the House of Representatives in 1976 then the Senate in 1987, the 78-year-old veteran lawmaker is the longest serving woman in congressional history, and she's known as one of the fiercest fighters for women, families and the middle class.
"I had to ask myself this question: Who am I campaigning for? Am I campaigning for me? Or am I campaigning for my constituents? I had to decide how to spend my time: fighting for my job, or fighting for their job," she said during her announcement.
It was that pro-active, straight-forward attitude that won the hearts of more than just voters in Maryland 38 years ago. She also earned the respect of her colleagues, both fellow Democrats and Republicans.
During a tribute to Mikulski, Sen. Chuck Schumer said, "She's the real deal. She knows where she came from. She has never forgotten where she came from."
And Kay Bailey Hutchison said, "The impact of this 4'11" mighty-might is impact of ten times. She has made an impact in Congress and an impact on America, because she is relentless, she is reasonable, she understands an issue and she understands the importance of listening as well as talking. She is effective."
While Hillary Clinton is widely known for the pantsuit, Mikulski actually paved the way for the trend. In 1993, when women were required to wear dresses or skirts on the Senate floor, the Maryland Democrat donned a pair of pants with Sen. Carol Moseley Braun. Others followed soon after.
But her fight for women extended far beyond the closet.
When Mikulski was first elected there was only one other woman in the Senate -- now there are 20. Over her five terms she became known as the "Dean of Women" for creating and mentoring a sort of "Senate sisterhood" among female members of both parties.
For two decades, Mikulski hosted monthly dinners for Senate women to discuss anything from home life to national health care.
In an essay for Politico, Sen. Barbara Boxer, who also announced her retirement this year, said when she first considered running for the Senate, she knew she had to talk to Mikulski.
"Sen. Mikulski has never been satisfied just making history herself - she wanted to blaze a trail wide enough for all of us to follow. As she said: 'Some women stare out the window waiting for Prince Charming. I stare out the window waiting for more women senators!'"
Mikulski will spend the two remaining years of her term championing for Maryland residents, passing on the inspiration that, "Each one of us can make a difference. Together we can make a change."