In 2009 a transcript of Abraham Lincoln provided the world's oldest example of a smiley - 1862.
That record appears to have been blown completely out of the water with the this...
... from 1648.
This is Robert Herrick's 1648 poem "To Fortune". Literary critic Levi Stahl has cross checked later editions of the work against his own copy and found the same symbol.
He found an earlier version of the text from the 19th century that did not contain the parentheses and so argues - rather convincingly - it's the addition of a modern editor.
On a more positive note, we came across the Wikipedia entry for 'Emoticon' while writing this and found possibly the finest crafted sentence ever...
An emoticon (/ɨˈmoʊtɨkɒn/) is a metacommunicative pictorial representation of a facial expression which in the absence of body language and prosody serves to draw a receiver's attention to the tenor or temper of a sender's nominal verbal communication, changing and improving its interpretation.