Some years there are butterflies in my yard, and some years there aren't. This year we have a plethora of Red Admirals, aka Vanessa cardui (Linnaeus). I read somewhere that they like thistle blossoms, which is too bad; last weekend we frantically yanked up all the Canada thistle because it was starting to bloom. Fortunately, Red Admirals like other flowers as well, including Scabiosa (I think this is 'Butterfly Blue').
The only other butterflies I have seen are Cabbage Whites (Pieris rapae), never a welcome sight.