Why are places like England more accepting to interracial dating than America?

I only ask because when I first started dating my boyfriend, it was great. He is super sweet and funny; however, the more we went out places (not everywhere) people would look. And I would get so mad, it would really even make us argue. He white and I'm black, so can understand there will be problems but geez! When we went to Europe on a trip, people there didn't even spare a glance. It was normal. I noticed so many interracial couples from asain to indian and black to white. they were so much more chill about things. why is that?