On this web site off to the left is an animated gif showing prez election vote percents by county divided up colorwise by red=Republican blue=Democratic green=Other.
direct link to full-screen version of map
One thing that caught my eye during the rotations was the blast of green / yellowgreen in the deep south 1960-1968. Well, 1968 of course was George Wallace (Am Independence Party) and I knew all about that one (he did well enough to snag a handful of electoral votes), but it had shown up in milder form in the previous two elections as well (mostly Mississippi and Alabama and a bit of Louisiana). I found references to Harry Bird of Virginia running as a 3rd party candidate in 1960, so I assume that accounts for the green in Mississippi and parts of Louisiana (?) (although why not in Virginia if it’s Byrd?); but in 1964 I can find nary a mention of any 3rd party candidate who would have polled well enough to put all that green into northern Alabama (???)…