Two days after officially retiring, former Supreme Court Justice Sandra Day O'Connor starts her new job — teaching law at the University of Arizona.

O'Connor will teach a two-week course about the U.S. Supreme Court starting Thursday.

The self-described Arizona cowgirl announced her retirement in July but it wasn't official until Tuesday, when Samuel Alito Jr. was confirmed as her replacement.

O'Connor, who grew up on a ranch in the southeastern part of the state, joined the nation's highest court in 1981, when President Ronald Reagan picked her as its first female justice.

More than a third of the students at the university's James E. Rogers College of Law — 178 future lawyers — have enrolled in the course, said university spokeswoman Nancy Stanley. O'Connor served in the state Legislature and as a state judge before going to the Supreme Court.