Nancy Reagan, the former actress who was fiercely protective of husband Ronald Reagan through a Hollywood career, eight years in the White House, an assassination attempt and her husband's Alzheimer's disease, died on Sunday at age 94, the Reagan library said.
Michael Reagan said on Twitter he was saddened by his stepmother's death. "She is once again with the man she loved," he wrote.
Reagan became one of the most influential first ladies in US history during her Republican husband's presidency from 1981 to 1989,
Her husband, who affectionately called her "Mommy" while she called him "Ronnie," died in 2004 after a long struggle with Alzheimer's, the progressive brain disorder that destroys memory.
As Nancy Davis, she was a Hollywood actress during the 1940s and 1950s and married Reagan, a prominent film actor, in 1952. She then served as first lady of California during her husband's stint as California governor from 1967 to 1975 before moving into the White House after his decisive victory over incumbent Democratic President Jimmy Carter in 1980.
Her most publicised project as first lady was the "Just Say No" anti-drug campaign. After her husband developed Alzheimer's disease, she became an advocate for discovering a cure.
She was diminutive and publicly soft spoken but Nancy Reagan's strong will, high-tone tastes and clout with her husband made her a controversial figure during his presidency.
As Reagan's wife, political partner and adviser, she became one of America's most potent first ladies, alongside the likes of Franklin Roosevelt's wife, Eleanor, Woodrow Wilson's wife, Edith, and Bill Clinton's wife, Hillary.
Tiny and frail in her later years, Reagan devoted her time to caring for her ailing husband at their home in Los Angeles' exclusive Bel Air enclave. She was always a stickler for protocol and detail and stoically presided over the former president's week long funeral and celebration of his life in June 2004.
Mrs. Reagan had her left breast surgically removed in October 1987 after a cancerous tumour was discovered.
She was born Anne Frances Robbins into a crumbling marriage in New York on July 6, 1921. Her car-salesman father deserted the family soon after, and her mother, actress Edith Luckett Robbins, resumed her show business career two years later.
In 1929, her mother married Loyal Davis, a neurosurgeon. Nancy came to adore him, even taking his name, and the doctor was believed to have had considerable influence on his eventual son-in-law's shift from Democrat to Republican years later.
After graduation from elite Smith College, she worked as a nurse's aide, then began a stage career in New York. Starting in 1949, she had an eight-year career in films including one - "Hellcats of the Navy" (1957) - co-starring with Ronald Reagan.
She often took supporting roles but had starring roles like one in the 1953 B-movie "Donovan's Brain" about a scientist who kept the brain of a dead millionaire alive in a tank.
Ronald Reagan divorced another actress, Jane Wyman, in 1948. They had a daughter, Maureen, and adopted a son, Michael.
At the time, Ronald Reagan headed the Screen Actors Guild. Davis was stunned when an industry newspaper published a list of communist sympathizers and her name was included (it turned out to be a reference to another actress of the same name). She sought out her future husband for assistance.
During the early years of the Cold War, Hollywood blacklisted - refused to employ - numerous people accused of holding communist views, ruining many careers and lives.
Ronald and Nancy Reagan got married in 1952 and had two children together - Patti Davis, an actress, and Ron Jr., who pursued careers in ballet and television.