Diane Sawyer started in TV in Louisville, Kentucky, then became a press aide for the White House during the Nixon administration (she also assisted Nixon with his memoirs). She ended up at CBS in the late 1970s, eventually getting a co-anchor spot on 60 Minutes in 1984.

In the 1990s she worked for ABC, co-hosting PrimeTime Live and 20/20, earning a reputation for tough investigative reports and interviews with world leaders. In 1999 she was named anchor for Good Morning America.

Source: who2.com