Bloomberg was born and raised in Medford, Massachusetts, a suburb of Boston. He made his fortune selling financial-information terminals to Wall Street firms. Bloomberg L.P also began a radio network (the flagship station is 1130 WBBR-AM in New York City). Prior to founding the company, he was general partner at Salomon Brothers, where he headed equity trading, sales and, later, systems development.
In 2001 he defeated Mark J. Green in the mayoral election to replace Rudy Giuliani, who was required to leave office by term limits. A lifelong Democrat, Bloomberg ran on the Republican ticket to avoid the Democratic primaries.
Michael Bloomberg is a member of the Phi Kappa Psi fraternal organization. He graduated from Johns Hopkins University in 1964 with a BS in electrical engineering and Harvard University with a Master of Business Administration degree. Bloomberg has donated $100 million to Johns Hopkins University.
Bloomberg has supported a number of measures to restrict public smoking during his time as mayor.