"Today we have lost the comfort of Elizabeth's presence but she remains the heart of this family," the Edwards family says in a statement. "We love her and will never know anyone more inspiring or full of life."
She died at her home in Chapel Hill, N.C., surrounded by her family.
"On behalf of Elizabeth we want to express our gratitude to the thousands of kindred spirits who moved and inspired her along the way," the statement adds. "Your support and prayers touched our entire family."
President Barack Obama called Edwards's estranged husband, former Democratic North Carolina Sen. John Edwards, and their daughter, Cate, to offer condolences.
"In her life, Elizabeth Edwards knew tragedy and pain. Many others would have turned inward; many others in the face of such adversity would have given up," Obama and First Lady Michelle say in a statement. "But through all that she endured, Elizabeth revealed a kind of fortitude and grace that will long remain a source of inspiration. Our thoughts and prayers are with her family and friends."
Former President Bill Clinton also sent his condolences saying, "With the passing of Elizabeth Edwards, America has lost a symbol of strength, hope, and humanity. Her children have lost a loving mother, her friends a wise counselor. My prayers are with them."
On Dec. 6, 2010, it was announced that Edwards's doctors decided that further treatment for her breast cancer would be unproductive and that she only had a short time left to live.
That same day, on her Facebook page, Edwards thanked supporters and wrote, "The days of our lives, for all of us, are numbered. We know that. And yes, there are certainly times when we aren't able to muster as much strength and patience as we would like. It's called being human."
First diagnosed with cancer in 2004, Edwards went into remission until the 2008 presidential campaign.
Her husband declined to withdraw from the race – a decision he announced at a press conference with his wife stoically standing at his side.
A few months later, however, he was effectively forced out of his bid for the White House by frontrunners Hillary Clinton and Barack Obama.
In a heartbreaking later episode that at first brought denials from John Edwards and then a frank admission, the former politician acknowledged fathering a child with a videographer who worked for his campaign. John and Elizabeth Edwards separated in January 2010, after three decades of marriage.
A native of Jacksonville, Fla., and an attorney by training (she and John met in law school at the University of North Carolina, and married in 1977), Elizabeth Edwards is survived by three children, ranging in age from 28 to 10: Cate, Emma Claire and Jack. Her eldest child, Wade, was killed in a 1996 car accident when he was 16.
As she wrote on the day it was announced she would stop having treatment, "I have found that in the simple act of living with hope, and in the daily effort to have a positive impact in the world, the days I do have are made all the more meaningful and precious. And for that I am grateful."