Kara McCullough from the US capital will go on to represent the United States at the Miss Universe contest.
"We regulate nuclear power plants. And I have a personal community outreach program called science exploration for kids," said McCullough, 25.
McCullough was born in Italy and also lived in Japan, South Korea, Hawaii. She was raised in the southern US state of Virginia.
As Miss USA "my plan is to inspire and encourage so many children and women (to enter) the science, technology, engineering and mathematics fields," she said.
The pageant included a field of five new immigrants who spoke on air about the importance of diversity -- as if to refute US President Donald Trump's less than welcoming stand toward some immigrants and refugees.
Indeed, the runner up was Chhavi Verg, Miss New Jersey, who was born in India and speaks Hindi and Spanish.
The pageant decides who will be the US representative in the Miss Universe contest.
The Miss USA and Miss Universe pageants for years were co-owned by billionaire Trump.
However in June 2015 the NBC network severed its ties with the now president after his offensive comments on Mexican immigrants. Following legal action Trump sold his stake in the pageants to a talent management group.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)