She's already won the title as the longest serving female in the U.S. Senate. Now, Senator Barbara Mikulski, D-Md., this weekend will become the longest serving female member in all of Congress.

On Saturday the 75-year-old Mikulski will log 12,858 days of service, which will unseat Republican Edith Nourse Rogers of Massachusetts who previously held the title after serving in Congress from 1925-1960.

In an interview last year with ABC's Diane Sawyer when she became the longest serving female Senator, Mikulski says she never thought of herself as a historical figure.

"To me history is powdered wigs," she joked last year.

Mikulski, who stands at just 4'11? and is known as one of the fiercest fighters in the Senate, is making history one more time with the new title. She first came to Congress in 1976, representing Maryland's 3rd district in the House of Representatives for 10 years. In 1986, she ran for senate and won, the first female Democratic Senator elected without succeeding her husband or father. She's been serving in the senate ever since.

Mikulski is often referred to as a "Dean of the Women" in the Senate.

"As the dean, she builds coalitions - proving that the Senate women are not solo acts, but work together to get things done," Senator Mikulski's website says.

Mikulski's colleagues in the Senate have already begun to celebrate her milestone.

"Congrats @SenatorBarb. MD's Barbara Mikulski to become longest-serving female Member of Congress," Sen. Jeanne Shaheen, D-NH., tweeted today.

There are currently 17 female Senators and 76 female members of the House of Representatives.