(CNN) – The Daley-era in Chicago ended Monday when Rahm Emanuel took over the reins as the Windy City's 46th mayor.
Emanuel assumed the new role by taking the oath of office at 12:23 p.m. ET in the Amy Morton of Steppenwolf Theater. Vice President Joe Biden, Labor Secretary Hilda Solis, Treasury Secretary Timothy Geithner and White House Chief of Staff William M. Daley, the former mayor's brother were in attendance.
"Chicago is a different city today than the one Mayor Daley inherited, thanks to all he did," Emanuel said. "New times demand new answers; old problems cry out for better results. This morning, we leave behind the old ways and old divisions and begin a new day for Chicago."
Emanuel, 51 was a key aide to former President Bill Clinton and a three-term Illinois congressman before serving as chief of staff to President Barack Obama.
The skilled political operative, who chaired the Democratic Congressional Campaign Committee during the 2006 election, won the four-way mayoral race in February with over 55 percent of the vote, beating former Chicago School board head Gerry Chino, City Clerk Miguel del Valle and former Sen. Carol Moseley Braun.
Emanuel canvassed the city during the campaign delivering a series of high-profile campaign speeches and making 257 informal stops throughout the city. He proposed a series of tax cuts, as well as increasing levies for luxury services and said he would work toward a balanced budget.
But he was plagued throughout the campaign by accusations that he was not a legal Chicago resident and therefore could not run for the office. The charge stemmed from a house he rented while serving in the Obama administration.
After a series of conflicting rulings, the state Supreme Court ruled unanimously that Emanuel's name should be on the ballot.
And now, as the new mayor, Emanuel said he is ready for the daunting task ahead.
"All of us have a role to play in writing Chicago's next chapter," Emanuel said. "None of what we must overcome will be easy, but in my heart I know this: The challenges for the city of Chicago are no match for the character of the people of Chicago."
– CNN Senior Producer Kevin Bohn contributed to this report