Why does the President pardon the turkey?

In a tradition we might have trouble explaining to foreigners, every November the President of the United States pardons a turkey. As Americans we accept this as normal, but how did it start? 

The story goes that President Abraham Lincoln’s son Tad persuaded his dad to spare their Christmas Turkey and keep it as a pet, whom they named Jack. 

Whether or not that’s true, the first documented turkey pardon was given by President John F. Kennedy in 1963. He said, “Let’s keep him going,” and it was actually The Washington Post that used the term “pardon.”

The annual turkey presentations continued, but the Presidential pardon didn't catch on.

According to the White House, it wasn't until 1989 that pardoning resurfaced as part of the celebration. That year, President George H.W. Bush started what has become the tradition upheld by every president since. 

Of course, the turkey doesn’t get to stay (sorry Tad, no turkeys for pets at the White House). Instead they’re sent away to live on a farm or petting zoo, blissfully unaware of their good luck.