
Of course, they smiled for informal pictures before that.
Many cameras captured FDR with his famous smile. Rockwell painted Eisenhower for two Post covers in a rubbery grin. Jimmy Carter’s toothy smile was a big subject during his campaign.
But for the official and semi-official pictures, up until 30 or 40 years ago, presidents usually kept their faces dignified and serious. After Reagan, the full-on toothy smile (which is a very different challenge to paint) was here to stay.

Are there other jobs that still demand a serious portrait, such as a Supreme Court justice, district attorney, or an undertaker?