Whiting threw 21.66 and Cantwell 21.28.
Olympic medalists Stephanie Brown Trafton and Jenn Suhr also booked return trips to the Olympics in women’s field events.
Surprise 2008 gold medalist Brown Trafton dominated the discus, closing out the competition with a throw of 65.18m.
Suhr, the Beijing silver medalist, cleared 4.6m in the pole vault.
Collegian Marquise Goodwin won the long jump on his final leap, going 8.33m to defeat William Claye.
The trials select the US team for the London Games and only the top three finishers in each event book a spot, provided they meet the qualifying standard.