"This evening, I want to acknowledge and honor the women of this world, whose wise voices for much too long have been excluded and discounted," Mozambique-born Heinz Kerry, 65, told the enthusiastic audience of delegates and alternates inside the FleetCenter in Boston.

The Boston Tea Party

The multilingual — she speaks French, Italian, Spanish and Portuguese — daughter of a Portuguese doctor and his British-born wife, she became a US citizen in 1971. Her speech, delivered in a soft Portuguese lilt, was scripted,  a change in style for a woman known for her off-the-cuff comments, said CNN.

Heinz Kerry grabbed headlines at the start of the convention after telling a reporter to "shove it" when he questioned her about a speech she had given -- in which she touched on the erosion of civility in politics.

'Most US voters know little about Kerry'

The widow of a Republican senator and the wife now of a Democratic senator, Heinz Kerry addressed her reputation for speaking her mind -- at times bluntly, said CNN.

"My right to speak my mind, to have a voice, to be what some have called 'opinionated' is a right I deeply and profoundly cherish," she said to loud cheers. "My only hope is that, one day soon, women who have all earned the right to their opinions -- instead of being called 'opinionated' will be called smart and well-informed, just like men."

Describing her husband "a fighter," she said John Kerry would lead the nation by "showing the face, not of our fears, but of our hopes." Referring to his military service during the Vietnam War, she said: "He earned his medals the old-fashioned way, by putting his life on the line for his country."

"We can and we will create good, competitive and sustainable jobs while still protecting the air we breathe, the water we drink, and the health of our children, because good environmental policy is good economics," she said. "I have a very personal feeling about how special America is, and I know how precious freedom is," Heinz Kerry said.

Slide Show: Breakfast with Kerry

On Iraq, she said that development of alternative fuels "will guarantee that not only will no American boy or girl go to war because of our dependency on foreign oil, but also that our economic security will forever become independent of this need."

Heinz Kerry inherited a huge fortune estimated at $500 million after her first husband — John Heinz, a banker who later became a US senator from Pennsylvania--was killed in a plane accident in 1991. She married Kerry in 1995, and became a Democrat in 2003. She has three sons from her former marriage, one of whom, Chris, has been a high-profile campaigner for his stepfather. Introduced his mother Tuesday night, Chris Heinz described her "a true visionary," "a remarkable woman" and the "next first lady of the United States."