Democrat Tammy Baldwin has become the first openly gay politician to be sworn into the US Senate.

Earlier today, the junior senator for Wisconsin swore the oath of office to US Vice-President Joe Biden.

In her election night speech last November, Ms Baldwin said: ““I’m very aware that I will have the honor to be the first woman senator from Wisconsin. And I’m well aware that I will be the first openly gay member of the United States Senate.”

Chuck Wolfe of the Gay and Lesbian Victory Fund said today: “LGBT Americans have finally broken through a glass ceiling that held firm for more than two centuries.

“This is real progress – a victory for us all. And this is a moment to smile, celebrate and raise a glass to toast a record number of out federal lawmakers.”

After announcing her run for the US Senate in September of last year, Joe Solmonese of the Human Rights Campaign said: “Tammy Baldwin’s candidacy for the US Senate is monumental for both the state of Wisconsin and the country’s LGBT community”.

He added: “Tammy has proven herself as an effective legislator over the course of her 13 years in congress.”

The 50-year-old is described as a strong supporter of LGBT, women’s rights and has pushed heavily for healthcare reform.

She was a staunch critic of Don’t Ask, Don’t Tell, America’s previous ban on openly gay members of the armed forces.

Ms Baldwin was first elected to political office in 1986 on the Dane County Board of Supervisors in Madison, Wisconsin.

She had previously served as the US Representative for Wisconsin’s 2nd congressional district.