The google flight site can give a pretty good depiction by searching all AA US hubs as an origin, and "EUROPE" as destination with a date. In this link I used July 13 to get the full map of nonstop Europe destinations from MIA/PHL/JFK/ORD/DFW/LAX
https://www.google.com/flights?hl=en...03052;t:e;tt:o