Maryland Democratic Senator Barbara Mikulski announced this week she would not seek re-election in 2016, leaving a 4-foot-11-inch sized hole in the halls of the Senate.
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."
Mikulski was the first Democratic woman elected to a Senate seat in her own right and a few years later she made, of all things, a fashion statement.
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."