One happened today - Pope Francis spoke before Congress for about an hour. He's the fourth foreign leader to speak before a joint meeting of Congress - since he's the head of Vatican City he's considered to be both a religious and political leader.
The House website provides background:
- Foreign Leaders & Dignitaries Who Have Addressed the U.S. Congress.
And - of course - Wikipedia has a list of all joint meeting and sessions of Congress since day one.
- Click here for it.
As well as information about the event.
- Click here for that.