First off, good pics! I love to see variety like that...
Anyway, if those aircraft were LAX/SFO/PHX/DEN bound, they would usually enter North America over Canada. So...they were probably traveling to cities east of ORD. Even then, if they were ORD bound, they would be flying much farther north than BOS. These were probably flights to either: JFK, EWR, IAD, MCO, ATL, or MIA. TPA, maybe?
San Diego, CA