American Airlines has low prices for spring flights to select locations in Europe.
Availability is early March to early May.
Departure Cities:
Atlanta (ATL)
Detroit (DTW)
Minneapolis (MSP)
Cincinnati (CVG)
Salt Lake City (SLC)
Memphis (MEM)
Arrival Cities (Example prices from ATL):
Amsterdam (AMS) from $381
Rome (FCO) from $393
Milan (MXP) from $408
Paris (CDG) from $425
Additional sub-$500 prices to Stockholm (ARN), Marseille (MRS), Frankfurt (FRA), London (LHR), Manchester (MAN), and Munich (MUN) (potentially more) depending on departure city.
Example fare:
MEM-AMS, March 23rd-April 6th $376 RT.
Use Google Flights Explore to find cheapest dates/cheapest cities from your airport. Prices may be even cheaper than shown on Google Flights Explorer when you go to book.