Third party candidate in Prez election drawing AL votes in 1964?

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 (???)…

Looks like they were unpledged Democratic electors. As I’m reading it, this was a strategy used by some Southern Democrats in the '50s & '60s, in an effort to leverage more concessions from the national party. See the Wiki article on unpledged electors for a few more details.

Byrd didn’t actively seek the presidency in 1960. He received the votes of fourteen unpledged electors (see the Wiki article) from Alabama and Mississippi, plus one faithless Republican elector from Oklahoma. Since the Virginia Democratic Party never chose to pursue an unpledged elector strategy, he received no electoral votes from Virginia.