American presidents started smiling for their official portraits in the mid 1970s or so.
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.
Why the change? Was it the inevitable outcome of photography or was it the result of campaigning on television?
Are there other jobs that still demand a serious portrait, such as a Supreme Court justice, district attorney, or an undertaker?