From the Daily Dot:
It was total bullshit: We knew nothing about Amelia Bedelia or the author of the series, Peggy Parish, let alone that she’d been a maid in Cameroon or collected many hats. It was the kind of ridiculous, vaguely humorous prank stoned college students pull, without any expectation that anyone would ever take it seriously. “I feel like we sort of did it with the intention of seeing how fast it would take to get it taken down” by Wikipedia’s legion of editors, Evan says.
But apparently, it hadn’t been taken down at all. There it was, five and a half years later, being tweeted as fact by relatively well-known members of the New York City media establishment. And a quick search of “Amelia Bedelia Cameroon” proved that Kang and Wikipedia weren’t the only ones taken in by the joke.
My favorite part is that Herman Parish, Peggy's nephew and the author of the later books, WAS ALSO TAKEN IN BY THE HOAX.