I am delighted to announce that I've done some research on the subject and am now prepared to share with you my discoveries:
The exclamation point first appeared in print in the late 1400's. It was discovered by the "court-appointed" scribe of Christopher Columbus shortly after landing in The New World and encountering a turkey. Unfortunately, the mark was appropriated by the Spanish Inquisition upon his return and lost to history for some time.
It was subsequently re-discovered centuries later by William Blake in one of his visions.
Originally known as the "note of admiration" it took several incarnations for this controversial punctuation mark to settle into its modern day moniker. Other candidates (some still in use among archaic cultures) included:
It took considerable lobbying on the part of Benjamin Franklin to effect the final change and guarantee its security during the Continental Congress of 1774. Nevertheless, perhaps due to the known sexual proclivities of its most outspoken proponent, use of the exclamation point was considered "poor taste" for the next 200 years.
[DID YOU KNOW: Joseph McCarthy organized a special task force to secretly remove the exclamation point from Public Libraries nationwide? The effort failed, of course, thanks in no small part to the valiant efforts and cut-throat tactics of the now infamous Librarian Brigade.]
It wasn't until 1970 (after Middle America had been sexually liberated with the help of mind-altering substances) that the exclamation point appeared on the very first factory-produced typewriter.
Previous to this, all known exclamation marks in existence were the property of the very very rich, who made their money renting the artifacts at exorbitant rates to museums and any publishing houses that could afford them. As a result, it was the common practice of newspapermen, poets and other subversives to type a period-backspace-apostrophe.
The subsequent shift in public perception helped bring the exclamation point from the comic book pages back into the realm of legitimate literature and turned Tom Wolfe, one of the mark's most flagrant "abusers," into an overnight success.
Wolfe's popularity and the resulting demand for exclamation points among the general public eventually forced the US government to sign trade agreements with Spain and several South American countries, importing billions of the marks in exchange for pre-bleached American wheat.
Which brings us, more or less, to today and the age of electronic text. More on this later...