Souter was born in Melrose, Massachusetts and spent most of his childhood and adolescence at his family's farm in Weare, New Hampshire. He was graduated from Harvard College, from which he received his A.B. After two years as a Rhodes Scholar at Magdalen College, Oxford, he received an A.B. in Jurisprudence from Oxford University and an M.A. in 1989. After receiving an LL.B. from Harvard Law School, he was an associate at Orr and Reno in Concord, New Hampshire from 1966 to 1968, when he became an Assistant Attorney General of New Hampshire. In 1971, he became Deputy Attorney General and in 1976, Attorney General of New Hampshire. In 1978, he was named an Associate Justice of the Superior Court of New Hampshire, and was appointed to the Supreme Court of New Hampshire as an Associate Justice in 1983. He became a Judge of the United States Court of Appeals for the First Circuit on May 25, 1990.
President George H. W. Bush nominated him as an Associate Justice of the Supreme Court, and he took his seat October 9, 1990. The United States Senate approved his seat 90 to 9. The press called him the "stealth justice," since his professional record provoked no real controversy.
Souter, along with Rehnquist and Breyer, has a reputation for being a strong guardian of the court's institutional integrity. Although appointed by a Republican president, he tends to side with liberals rather than the conservatives. He dissented from the Court's opinion on the Bush v. Gore election of 2000 case.
Souter enjoys mountain climbing in New Hampshire during the judicial off-season. He is Co-chair of the We the People National Advisory Committee.
After he was sworn in he said: "The first lesson, simple as it is, is that whatever court we're in, whatever we are doing, at the end of our task some human being is going to be affected. Some human life is going to be changed by what we do. And so we had better use every power of our minds and our hearts and our beings to get those rulings right."