To answer some questions...
There will 18 athletes per team covering 7 running events and 3 field events.
It's up to each team how they spread their athletes out but a likely scenario would be 2 per event per team in the running events and 1 athlete per event per team in the field events. So each running event would have 8 competitors and each field event would have 4 competitors.
There are two phases to the drafting of athletes. Yesterday's draft was phase one. These athletes actually receive a cash bonus for being drafted in this "draft phase".
But yesterday's draft only accounts for 8 of each team's 18 man/woman roster. The remainder of the athletes will be selected on July 16 thru a "free agent" draft. This will give team managers a chance to see how athletes do at USA's before finalizing their rosters.
The 7 running events for men and women are:
100
400
800
1500
110 hurdles
Steeple
4 mile road race (as part of a local Eugene road race. Community will have an opportunity to run with these drafted men and women in the same race).
The 3 field events for women are:
Shot put
Pole vault
Long jump
The 3 field events for men are:
Shot put
High jump
Triple jump
The Tracktown USA has more info on their website and if you google "Tracktown summer series" there are numerous articles that have been published on the event that you can read.
Hope this helps!