I wrote here about The Club of presidents, shortly after Barack Obama had visited George Bush in the White House.
I mentioned in that post that funerals of presidents and first ladies, presidential library dedications and inaugurations are the standard occasions for meetings of The Club. But every once in a while, there are other occasions that draw them together.
Today, Obama was back in the White House, and The Club had lunch together. Here is a New York Times report.
I recall at least two other past occasions, outside of the categories named above, when they got together:
When President Anwar Sadat of Egypt was assassinated in 1981, it was considered necessary to have top-level American representation at the funeral. However, due to security concerns, the incumbent president, Ronald Reagan, did not attend. Instead, all three living former presidents, Richard Nixon, Gerald Ford and Jimmy Carter, represented the United States. They flew over on the same plane. I've read that it was on that trip that Ford and Carter, who had run a somewhat nasty campaign against each other in 1976, buried the hatchet and started a friendship that lasted for the remainder of Ford's life.
On November 20, 2000, there was a White House dinner to observe the house's bicentennial. There were two months left in Bill Clinton's presidency. He and Hillary hosted Lady Bird Johnson, Jerry and Betty Ford, Jimmy and Rosalyn Carter, and George and Barbara Bush. Had the 2000 election been decided by then, I suppose they might have invited the president-elect and his wife, but the Florida electoral vote dispute was still going on.