A widespread fare war is happening today between Delta and American from most USA hubs for these two airlines to multiple cities across Europe. Fares are $400s to low $500s to Amsterdam, Paris, Milan, Zurich and many airports in Scandinavia and Spain.
Miami and New York airports have low fares with both OneWorld and SkyTeam airlines.
Discount Delta/SkyTeam fares from American Airlines hubs:
New York City JFK, LGA – Barcelona BCN $502 (many cities across Europe on sale).
* Phoenix PHX is an AA hub where I do not see low Delta fares to Europe at time of publishing.
Delta Airlines Dallas DAL Love Field – Atlanta ATL – Madrid MAD – ATL – DAL
American Airlines/Oneworld discount fares at Delta hubs:
Minneapolis MSP – Stockholm ARN $430 (many cities in Norway, Sweden and Denmark in $400s/low $500s).
New York City JFK, LGA – Barcelona $523 (many cities in Europe on sale).
Miami MIA – Amsterdam AMS $494 (American and Delta have similar low fares)
*Cincinnati CVG is a Delta hub where I do not see low AA fares to Europe at time of publishing.
American Airlines Atlanta ATL – Dallas DFW – Amsterdam AMS – DFW – ATL
$444.96 round trip Monday Sep 11 – Fri Sep 15
There may be more deals available today in this fare war between American/Oneworld and Delta/SkyTeam. These links will get you started.