Nancy Reagan worked in theatre and film before becoming a prominent political spouse and public campaigner. After stage appearances, including a role in the Broadway production of Lute Song, she signed with Metro-Goldwyn-Mayer in 1949. Working as Nancy Davis, she appeared in films including The Next Voice You Hear, Donovan's Brain and Hellcats of the Navy, the last alongside Ronald Reagan. Her screen career diminished as she concentrated on family life and her husband's political work.

As California's first lady from 1967 to 1975, she visited hospitals and supported wounded service members, older people and children with disabilities. Her involvement with the Foster Grandparent Program linked older volunteers with children needing individual attention.

In the White House from 1981 to 1989, she combined ceremonial responsibilities with an active interest in her husband's welfare and political standing. She organized official entertaining, supported restoration and furnishing projects and became a close adviser whose access gave her considerable informal influence. Public discussion of her clothing, expenditure and White House style sometimes overshadowed her charitable work. Her influence rested on personal relationships.

Her most visible initiative addressed drug and alcohol abuse among young people. The Just Say No campaign encouraged children to refuse drugs and drew attention through school visits, television appearances and prevention organizations. In 1985 she brought first ladies together for an international conference on drug abuse. Publicity did not establish that the campaign prevented addiction.

After leaving Washington, she supported the Reagan library and helped care for her husband following his diagnosis of Alzheimer's disease. She later advocated embryonic stem-cell research, taking a public position that differed from that of many conservative allies. She continued to represent his legacy after his death in 2004.