Democratic presidential candidate Joe Biden chose Senator Kamala Harris as his running mate. She is the first black woman to function in the position.
The California senator of Indian-Jamaican legacy deliberated the prime candidate for the role.
The former California attorney-general advising police amendment in the middle of anti-racism protests.
Mr Biden will confront President Donald Trump in the ballot vote on 3 November.
Vice-President Mike Pence stays the Republican office holder running mate.
No more than two other women chosen as vice-presidential candidates – Geraldine Ferraro by the Democrats in 1984 and Sarah Palin by the Republican party in 2008. Neither ended it to the White House.
A woman of colour never been chosen to a presidential ticket by any of the two major American political parties. No woman won the US presidency also.
Mr Biden tweeted saying that he had “the great honour” to call Ms Harris as his number two.
He portrayed her as “a fearless fighter for the little guy, and one of the country’s finest public servants”.