Her demise was announced on Friday by officials at the Gerald Ford library and museum. Details of her death and where she died were not immediately available.
As the first lady, from 1974 to 1977, she was a powerful advocate for women's health and rights, US President Barack Obama said in a statement. "Throughout her long and active life, Elizabeth Anne Ford (Betty) distinguished herself through her courage and compassion," he said.
In 1978, Betty disclosed that her use of alcohol and mood-altering prescription drugs had become a serious dependency. After her family confronted her with her problem, she agreed to enter the drug and alcohol rehabilitation programme at Long Beach Naval Hospital. Based on that experience, she came out with the Betty Ford Centre in Rancho Mirage in California, a facility which provides treatment for alcoholics and drug abusers.
Vice President Joe Biden said that throughout her life, "Betty displayed strength, courage and determination that provided hope for millions of Americans seeking a healthier, happier future." "Her legacy and work will live on through the millions of lives she has touched and the many more who will continue to look to her for inspiration," he said.
In a joint statement, former US president Bill Clinton and his wife Secretary of State Hillary Clinton said that as a staunch advocate for women's and equal rights, Betty paved the way for generations of women to follow. "Her courage, compassion and commitment to helping our nation deal with drug and alcohol abuse and addiction helped thousands of people to a successful recovery and in the process she helped to save countless families," they said.
Former US president George H W Bush said that his wife Barbara and he loved Betty very much. "She was a wonderful wife and mother; a great friend; and a courageous First Lady." Nancy Reagan, wife of former president Ronald Reagan, said Betty was Gerald Ford's strength through some very difficult days in the country's history. She said she admired her courage "in facing and sharing her personal struggles with all of us."
The Washington Post said, to the surprise of some and the consternation of others, Betty evolved as an activist first lady whose non-threatening manner coupled with her newfound celebrity provided the women's movement with an impressive ally. "Undaunted by critics, she campaigned for ratification of the ill-starred Equal Rights Amendment, championed liberalised abortion laws and lobbied her husband to name more women to policymaking government jobs," the daily said.
The New York Times said few first ladies have been as popular as Betty, and it was her frankness and lack of pretense that made her so. "She spoke often in support of the Equal Rights Amendment, endorsed legalised abortion, discussed premarital sex and revealed that she intended to share a bed with her husband in the White House," it said.
Betty's husband, who died in 2006, was a longtime Michigan Congressman. He served as Richard Nixon's vice president before the Watergate scandal led him to succeed Nixon, who resigned on August 9, 1974.
Image: Former US president Gerald Ford and his wife Betty | Photograph: Mark Wilson/Reuters