Watching this relic of an American icon is like discovering your grandpa's love letters to someone else's grandma. What a paradigm shift! For the full story on why the main character is called Pope and not Post, check out the Wikipedia page on Mister Ed. To make it short, Walter R Brooks, the author behind the Mr Ed franchise, began writing stories about Ed the Talking Horse in 1937. They were published mostly in the long-extinct Liberty magazine. In those stories, while a man named Wilbur does befriend a talking horse, both he and the horse are, well, booze-hounds. Wilbur's beautiful exotic wife doesn't like him, as the older man is unable to perform his, er, "husbanding chores" let's say. So she spends all her days partying with boy toys and spending his money. Thus, Wilbur's faithful steed helps him wreak revenge on his faithless wife. Pretty Shakespearean, all in all.
While Drunks were seen as amusing back in the day, by the early TV era they were unacceptable as main characters. Thus a sober protagonist, reborn as Wilbur Post, and his caring wife Carol, needed to replace them. That didn't happen overnight--it took three years from this attempt to get all the details right. So from the page in the late 1930s to the TV screen in 1961, we see an interesting evolution.
Actor Scott McKay was game to play Wilbur, but he lacked the comic zip Alan Young brought along. By 1961 Young already had more than 20 years success as a radio and television comedian.
Mister Ed was corny and poorly written, but it's success all over the world proved that American junk TV had some kind of zing no other country could provide. C'mon, who wouldn't want a horse than could surf or fly a space capsule?