Could this be an early example of an emoticon?
I vote for "misinterpretation of something that is perfectly grammatical for that era." I've seen plenty of 19th-century cases where a comma or (less commonly) a semicolon was placed before a closing parenthesis rather than after. All that makes this case notable is that the punctuation follows the word "laughter."A historical newspaper specialist at the digital archival company Proquest believes he has found an example of a sideways winking smiley face embedded in The New York Times transcript of an 1862 speech given by President Lincoln. Other historians are not so sure, saying the semicolon alongside a closed parenthesis is either a mistake or a misinterpretation of something that is perfectly grammatical for that era. [Link]