Sen. Barack Obama’s grandmother, Madelyn Dunham, died early Monday morning in Hawaii after a long battle with cancer, the Democratic presidential candidate said in a statement.

Dunham was 86-years-old.

Dunham helped raise Obama while his mother was working in Indonesia, which Obama described in great detail in his memoir Dreams From My Father.

She died hours before she would learn whether her grandson–who is leading Republican John McCain in the polls–would make history as the first African American to be elected President of the United States.

Obama said his grandmother, who he referred to as “Toot,” “was the cornerstone of our family, and a woman of extraordinary accomplishment, strength, and humility. She was the person who encouraged and allowed us to take chances.”

In a joint statement released with his sister, Maya Soetoro-Ng, Obama said his grandmother “died peacefully.” Obama learned of his grandmother’s death during a campaign stop in Jacksonville, Florida.

“Our family wants to thank all of those who sent flowers, cards, well-wishes, and prayers during this difficult time. It brought our grandmother and us great comfort,” the statement said. “Our grandmother was a private woman, and we will respect her wish for a small private ceremony to be held at a later date. In lieu of flowers, we ask that you make a donation to any worthy organization in search of a cure for cancer.”

Obama interrupted his campaign for two days late last month to fly to Hawaii to spend time with his grandmother who had taken a turn for the worst. He said the decision to fly to travel to Hawaii during the height of the presidential campaign was important for him because he never got the chance to say goodbye to his mother, who died of ovarian cancer in 1995. 

“I got there too late,” Obama said of his mother, who died at the age of 53, during a CBS News interview last month. He said he wanted to make sure “that I don’t make the same mistake twice.”

In an interview with ABC’s “Good Morning America” last month Obama said his grandmother was “gravely ill. We weren’t sure and I’m still not sure whether she makes it to Election Day.”

“We’re all praying and we hope she does, but one of the things I want to make sure of is I had a chance to sit down with her and to talk to her. She’s still alert and she’s still got all her faculties. And I want to make sure that I don’t miss that opportunity,” he said.

Obama paid tribute to Dunham during his acceptance speech at the Democratic National Convention in August, where he officially accepted the Democratic nomination for president. 

“She’s the one who put off buying a new car or a new dress for herself so that I could have a better life,” he said. “She poured everything she had into me. And although she can no longer travel, I know that she’s watching tonight, and that tonight is her night as well.”