Granny D: You're never too old to raise a little hell
Doris Haddock, who walked across the US at the age of 89 to press for changes in election campaign funding, has died at her home in New Hampshire.
Granny D, as she was widely known, trekked 3,200 miles (5,150km) in 1999 and 2000 to draw attention to the high cost of running for office in the US.
A candidate had "to sell his soul" or be a multi-millionaire, she told the BBC during her journey.
In 2004, she ran for the US Senate for the Democrats, losing 66% to 34%.
On 1 January 1999, Granny D set out on her walk across the US, covering about 10 miles a day, six days a week.
Speaking about the then presidential race, she said the amount of money being thrown about was "obscene".
"This country has become one in which, in order to run for office, a poor man has to sell his soul, or he has to be a multi-millionaire. That's not democracy," she said.
Granny D's aim was to press Congress to plug loopholes in campaign laws that allowed what was known as "soft money" from corporations, trade unions, and interest groups to influence political campaigns.
In 2002, Congress passed the Bipartisan Campaign Reform Act (widely known as the McCain-Feingold act after the senators who proposed it), which banned national political party committees from accepting or spending soft money contributions.
In another development, in January this year the US Supreme Court overturned long-standing limits on how much companies could spend on political campaigns.
After her walk, Granny D kept campaigning. In 2004, she jumped into the race for the US senate at the last minute, losing New Hampshire to the Republican incumbent Judd Gregg.
"We are always saddened when someone with a genuine commitment to their values and principles passes away," New Hampshire Republican Party Chairman John Sununu said. "Granny D was an unwavering advocate for her beliefs."
Granny D died at her home in Dublin, New Hampshire, on Tuesday just two months after celebrating her 100th birthday.
The subtitle of her autobiography was You're Never Too Old to Raise a Little Hell.