"I knew after that fifth throw that I was on the team, so I just wanted to let it rip, have some fun and see what happened," the 35-year-old told reporters.
"I definitely wanted to go for the win and do the same thing I did in 2012, getting the win and the (meet) record."
Gwen Berry, returning from a three-month suspension for using a prohibited medication, and collegian DeAnna Price both threw 73.09 metres to make the U.S. team. Berry finished ahead of Price in the final standings due to a better second throw.
Collegian Rudy Winkler claimed the men's competition but no one met the Olympic standard of 77.00 metres with the winner falling 24 centimetres short of the mark.
"I was real nervous on my first two throws," he said. "In the fourth round, I stayed connected and stayed with it until the end."
The Americans will not have a male hammer thrower at the Aug. 5-21 Olympics unless the International Association of Athletics Federations (IAAF) opts to fill out the field to a targeted 32 athletes.
Currently only 23 athletes worldwide have reached the standard.
"I'm not going to worry about it too much," Winkler said. "I'd love to go the Olympics but I'm just starting. I'll be around awhile."
Defending U.S. trials champion Kibwe Johnson came second with a throw of 75.11 metres and another collegian, Conor McCullough, took third at 74.16.
No other events were held on Wednesday but the competition will see a full schedule of disciplines on Thursday. The trials conclude on Sunday.
(Editing by John O'Brien)
