Alyssa Campanella of Los Angeles topped a field of 51 beauty queens to take the title at the Planet Hollywood Resort & Casino on the Las Vegas Strip. She strutted across the stage in a blue bikini with white polka dots and a dark turquoise evening gown with beading on its top.
She also answered a question about legalizing marijuana by saying she didn't think it should be fully legalized as a solution to help ailing economies.
"Well, I understand why that question would be asked, especially with today's economy, but I also understand that medical marijuana is very important to help those who need it medically," she said. "I'm not sure if it should be legalized, if it would really affect, with the drug war. I mean, it's abused today, unfortunately, so that's the only reason why I would kind of be a little bit against it, but medically it's OK."
Miss Tennessee Ashley Durham was the first runner-up, while contestants from Alabama and Texas placed third and fourth.
Campanella, a natural blonde, said she dyed her hair six years ago for a part in a play, for a "fiery" character with whom she found she had traits in common.
"It's really brought out the true Alyssa Campanella, I feel, and that's why I really enjoy being a redhead," she said.
Campanella replaces Miss USA 2010 Rima Fakih. The Michigan woman teared up as she walked across the stage for a final goodbye.
The pageant had three competitions: swimsuit, evening gown and interview question.
The contestants were whittled to 16 after the show's opening number, in which the beauty queens introduced themselves one-by-one. The top 16 were picked by preliminary judges through competitions and interviews during the week before the telecast. Celebrity judges picked the top eight after the swimsuit competition and the top 4 after the evening gown portion.