The term was used officially by the US government, including Dwight D. Eisenhower in 1954, with Operation Wetback, a project which was a mass deportation of undocumented Mexican immigrants.

For what its worth, I have to give the producers of the DVDs credit for retaining the word in the DVD package. They could have easily dubbed in a less controversial word, but instead they chose to give us
The Munsters
as it originally aired. I'd rather have
historically
correct over
politically
correct.

I remember seeing Golly on Benny Hill's and Dave Allen's shows. My friends and I are black, but we laughed up a storm when we saw him! I, too, am fed up with the PC police. Whenever I mention political correctness, my friend always says "Well, you wouldn't want to see a fat person called a 'pig', would you?" I replied "No. But the thing is now you can't even call a fat person 'fat'." Also, I can understand if the hero of the story has a prejudice (although it makes the character more three-dimensional), but when the villains can't even use slurs or insults, then things have gone
WAY
too far!
As to Grandpa's use of "wetback": it caught me off-guard because I wouldn't have expected that word to pop up in a show in the Sixties. I would have expected it more in the Seventies and Eighties. It probably wouldn't pop up now except on a cable show like "It's Always Sunny in Philadelphia" or something on HBO or Showtime.
Yippee: "For king!"
Yappee: "For country!"
Yahooie: "And, most of all, for 10 an hour!"

Golliwogg
was the name of a character originating in 1895.
Here's the full history of the Golliwog/Golliwogg.
http://www.ferris.edu/jimcrow/golliwog/