Michael Bernard Mukasey was born in the Bronx, New York, on July 28, 1941. He graduated from Columbia University in 1963, and received a law degree from Yale University in 1967. After law school, Mukasey worked in private practice from 1967 to 1972 in New York. In 1972, he became a prosecutor as an assistant United States attorney in the U.S. attorney's office in Manhattan. From 1976 to 1987, he worked at the private firm of Patterson Belknap Webb & Tyler. 

In 1987, President Ronald Reagan nominated Mukasey to the U.S. district court for the southern district of New York. From 2000 to 2006, he served as chief judge. During his tenure, he presided over hundreds of cases, including the trial involving a 1993 conspiracy to blow up New York City landmarks and the 2003 case of an American citizen accused of working with Al Qaeda to build a dirty bomb. Judge Mukasey was consistently praised for his fairness, talent, and preparedness; after the terrorist attacks of September 11, 2001, he was credited for the speed at which federal courthouses returned to normal operation. In 2006, he retired and returned to Patterson Belknap Webb & Tyler. 

In September 2007, President George W. Bush nominated Mukasey to become the attorney general of the United States. Many supported Mukasey's nomination because of his experience and integrity and his support of the administration's approach to national security. He was confirmed by the U.S. Senate and assumed office in November 2007. He served until the end of the Bush administration in 2009.