Popular Democrat Cory Booker was sworn in Thursday as the newest US senator, becoming the first African American elected to the Senate since Barack Obama in 2004.
Vice President Joe Biden officiated the noon swearing-in for Booker, whose stint as mayor of the gritty New Jersey city of Newark drew national attention and made him a rising star in his party.
He replaces Jeff Chiesa, who was appointed to temporarily fill the seat of senator Frank Lautenberg, who died in June at age 89.
Booker boosts the Democrats' Senate advantage over Republicans to 10 seats, 55-45, and Senate Majority Leader Harry Reid this week praised the 44-year-old as a "remarkable young man."
They hoped his arrival would pay quick dividends during a crunch period of votes on President Obama's nominees to various posts including judicial ones, and looming fiscal battles later this year.
Loud cheers and applause erupted from the gallery after Booker took the oath in the chamber, where he was put to work immediately, taking a procedural vote on a nominee barely 90 seconds after being sworn into office.
Many Democrats and only a handful of Republicans were on the floor for the ceremony, including Tim Scott, the chamber's only other black senator, who was appointed to the position to fill a vacancy.
Booker proved a capable mayor, but he gained national notoriety in part because of his savvy use of social media.
He regularly responds to requests from some of his 1.4 million Twitter followers, making him as much of a street-wise folk hero as a national politician.
Last year, Booker made headlines by rescuing a woman from a burning house. He also opened his home to Hurricane Sandy victims, helped residents shovel out of a huge snowstorm and brought diapers to a stranded new mom.
He was nicknamed "The Savior of Newark" for his efforts targeting inner-city problems.
Booker was class president at Stanford University, earned a law degree from Yale University and was a Rhodes scholar at Britain's Oxford University.
Watch video, courtesy of C-SPAN, below: