'Bumfuzzled' is not a commonly used word, but it entered the American English lexicon at the beginning of the 20th century. It was first used in the southern states to mean 'confused'. The 'American Heritage' dictionary claims the word may have derived from similar words, such as 'bamboozled'.

Whilst many dictionaries agree with 'American Heritage', other ideas have been put forward. 'Merriam-Webster Unabridged' suggests the word is an "alteration of English dialect, ‘dumfoozle’ and ‘dumfound.’" Tim Weiner, a writer for 'The Times', muses whether there is a link between 'bumfuzzled' and the British slang term 'bumf'. 'Bumf' is a shortened version of “bumfodder,” a derogatory name for toilet paper.

In 1999, the word was famously used in a speech by President Bill Clinton. "I can imagine the American people must be totally bumfuzzled." At the time of the speech, many people assumed Clinton had coined a new word.

The earliest known usage of the word 'bumfuzzled' was in American author William Nathaniel Harben's (1858-1919) 'Northern Georgia Sketches', published in 1900. He wrote the phrase, “Well, I’ll be liter’ly bumfuzzled!”

More Info: slate.com