Liberalism as a political creed and project has been kaput since 1914, though, paradoxically, it greatly influenced almost everything else in the run-up to that point to the extent that almost everyone is at least a little bit of a liberal, in a broad sense. If you think that's nonsense, try to draw up a list of points that would determine (roughly) whether or not someone is a liberal. You'll get my point soon enough.
American Liberalism is different, obviously. To misquote Herbert Morrison, American Liberalism is what Democratic Administrations do. And, in reality, not a lot else.
What about Thatcherism?