Kagan, 50, has been on a path to this moment for much of her adult life. In her senior year at Hunter College High School, she posed for one yearbook picture in a judge's black robe and holding a gavel. She graduated from Princeton University and Harvard.
She was a law clerk to U.S. Appeals Court Judge Abner Mikva on the District of Columbia Circuit, and in the 1987-88 term, to Supreme Court Justice Marshall.
She joined the Clinton administration in 1995, working as an associate White House counsel, then rising to deputy assistant to the president for domestic policy, then deputy director of the Domestic Policy Council.
Kagan's sterling resume, along with the documents released from the Clinton archive at the Judiciary Committee's request, show her to be a focused striver adept at maneuvering in a political environment. Much of her work involved weighing the legislative and political consequences of administration positions on topics from abortion rights to the Whitewater scandal that eventually led to Clinton's impeachment in the House of Representatives and acquittal in the Senate in 1999.
She helped draft letters for Clinton to send abortion opponents explaining his veto of a ban on an abortion method critics called "partial birth." Kagan had agreed with the decision to veto the bill, which did not include an exception for when the procedure might protect the woman's health.
Documents from the Clinton archives do not offer a full picture of Kagan's abortion-rights views.
During the Clinton years, Kagan worked to advance her career. After just a year with the administration and at age 36, she sought the top job in the Department of Justice's prestigious Office of Legal Counsel, which provides the president advice on constitutional issues. After an interview with the deputy White House chief of staff, she wrote a note reminding him that she had worked with then-Senate Judiciary Committee chairman Joe Biden on the 1993 confirmation hearings for Justice Ruth Bader Ginsburg. She added that Biden "strongly supports my selection" for the job. Yet that post went to someone else.
It was the Ginsburg hearings in the Senate, along with the confirmation hearings for Justice Stephen Breyer in 1994, that prompted Kagan to write in 1995 that members of the Senate Judiciary Committee "engage in a peculiar ritual dance, in which they propound their own views on constitutional law, but neither hope nor expect the nominee to respond in like manner."
In 1999 Clinton nominated Kagan to the U.S. Court of Appeals for the District of Columbia Circuit, which has been a stepping-stone for many justices, including Ginsburg and Antonin Scalia.
Her nomination stalled in the election year of 2000, and she never received a Senate vote.
Kagan in 1999 took a teaching position at Harvard Law School. In 2003, she became dean, the first woman named to the post. She gained a reputation as a leader who recruited conservative professors, including former Bush administration lawyer Jack Goldsmith, to the liberal-dominated campus.
When she testified before the Senate Judiciary Committee in 2009 for the solicitor general job, she told senators she had brought "a little bit of family from Cambridge" with her. Among the professors who accompanied Kagan, who never married and has no children, were Goldsmith and former Reagan administration solicitor general Charles Fried.