Rio 2016: Sydney McLaughlin, 16, qualifies for US Olympic team
Sydney McLaughlin became the youngest US athlete to be selected for the Olympics since Carol Lewis in 1980 after Sunday's trials in Oregon.
The 16-year-old finished third in the 400m hurdles to earn her spot in Rio.
Long jumper Lewis, the sister of nine-time Olympic gold medallist Carl, did not compete at the 1980 Moscow Games because the US boycotted the event.
Allyson Felix will not defend her 200m Olympic title in Rio after failing to qualify, but will race in the 400m.
McLaughlin, who set a new world junior record of 54.15 seconds, will be one of 77 American Olympic debutants at this summer's Games, which get under way on 5 August.
In gymnastics, three-time world champion Simone Biles, 19, qualified and will be joined in the five-woman team by Gabby Douglas, three-time Olympic medallist Aly Raisman, Madison Kocian and Laurie Hernandez.
Devon Allen, 21, ran the second fastest 110m hurdles of the year (13.03 seconds) in Saturday's final while Justin Gatlin and LaShawn Merritt both posted world-leading times in the 100m and 200m.
Gatlin clocked 9.80 seconds while Merritt ran 19.74 seconds in the 200m semi-final, although Gatlin beat him in the final.
Merritt is chasing a potential 200m-400m double in Rio, which has only been achieved once before, by Michael Johnson in 1996.
Men's head coach Vin Lananna said: "We have a lot of young athletes, but I think we have a good mixture of veterans as well that will pull the young athletes along."
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