Scott Brown says his dedication to hard work grew out of a difficult childhood
Until his overwhelming victory over Democratic candidate Martha Coakley, few people outside Massachusetts had ever heard of the photogenic and energetic Republican, Scott Brown.
He captured a seat that has been a stronghold of the Democrats for more than 50 years - that of the late Senator Edward Kennedy.
US media have called him "Senator Beefcake" - a lawyer and former model who posed almost naked for Cosmopolitan magazine in the 1980s.
Mr Brown was born in 1959 and grew up in Wakefield, Massachusetts, where his father served as a councillor for the city of Newburyport.
He says his dedication to hard work and family grew out of a difficult childhood.
His parents divorced when he was about a year old and both have since remarried three times.
"My mom was on welfare for a period of time," he said in a recent debate.
"I really came from nothing and worked my way up."
Mr Brown graduated from Wakefield High School in 1977 and then attended Tufts University, followed by law school in Boston.
A basketball player and athlete, he also dabbled in acting, appearing in TV commercials.
Using his photogenic looks, he also worked as a model. In 1982, while studying law, he posed in a centrefold - with a strategically placed crease - for Cosmopolitan, as the winner of the magazine's "America's Sexiest Man" competition.
He also enlisted in the National Guard and although never deployed, he has been on assignments to Paraguay and Kazakhstan.
He currently holds the rank of lieutenant colonel.
Mr Brown was awarded the Army Commendation Medal for service in home and security following the attacks of 9/11.
His political career began in 1992.
He served three terms as a State Representative and won his current State Senate seat in 2004.
In September 2009 he announced his intention to run for the US Senate seat which became vacant following the death of Senator Kennedy, saying the state "needs an independent thinker".
While initially trailing in the polls, he soon closed the gap on his Democratic rival with his energetic campaign, criss-crossing the state and holding daily press events.
His victory is the first for the Republicans in Massachusetts since 1972.
Politically conservative, he says that his military experience gives him a wider perspective on national security issues.
He supported President Barack Obama's decision last November to send more troops to Afghanistan.
But he has been critical of the president's proposals to reform US healthcare, vowing to vote against the healthcare package.
In his victory speech, he said the reforms "would raise taxes, destroy jobs and increase debt".