Democratic candidate John Kerry has chosen southern Senator John Edwards as his running mate for November's US presidential election.
"I am pleased to announce, that with your help, the next vice president of the United States will be Senator John Edwards of North Carolina," Mr Kerry told a boisterous rally in downtown Pittsburgh.
The presumptive Democratic nominee to face President George W. Bush in November, Mr Kerry credited Mr Edwards, a first-term senator and millionaire trial lawyer, with "guts, determination and political skills".
Mr Edwards had been Mr Kerry's chief rival in the party's primary selection process.
"He has shown courage and conviction as a champion for middle class Americans and those struggling to reach the middle class," Mr Kerry added.
Many Democrats were impressed with his charismatic style and populist message in his spirited campaign against Mr Kerry for the party's presidential nod. Mr Edwards has since raised money for Mr Kerry and had lobbied openly for number two spot. While he was not at Mr Kerry's side when the announcement was made, the two were to campaign together for the next few days.
The North Carolina senator held secret talks with Mr Kerry last week. Mr Kerry picked the smooth-talking populist over more seasoned politicians in hopes of injecting vigour and small-town appeal to the presidential ticket.
Until the last minute, Kerry advisers said their boss had recently signalled his interest in other candidates, including Mr Dick Gephardt, Mr Tom Vilsack and Mr Bob Graham.
The two men will be formally anointed later this month at the Democratic convention in Boston as the party's challengers to Mr Bush and Vice President Dick Cheney in the November election.
Republicans pounced on Mr Edwards's relative inexperience and lack of national security credentials with the United States at war against terrorism.
Mr Kerry e-mailed the name of his choice to more than a million subscribers to his website, underscoring the importance the Internet has played in his campaign. It was the first time a candidate used the Internet for such a crucial announcement. A campaign aide said about 150,000 people had signed up since Mr Kerry told reporters last week they would hear the news first.