I've pulled an image from the original issue of the Boston Weekly Magazine (November 12, 1803) if that helps.
I am both man and woman too,
And go to school as good boys do.
Will Shortz is looking for the answer to this riddle so submit your best answer to the NPR website.
Edit: The same rebus/riddle appeared in the December 1759 issue of The London Magazine. The answer given in the following month was that the answer is "I". But this answer was less than satisfying so Will picked a different answer.