This story shows both how small the world really is and just how ironic it can be.
Around the time of the Civil War, a student from Harvard was waiting to take a transfer train in Jersey City. Because of the people on the platform pushing and the area being crowded he was knocked into the gap. A man grabbed his collar and pulled him, saving him from injury.
What makes this story so interesting is who the two individuals were. The student was Robert Lincoln, the son of then President Abraham Lincoln. The man who pulled him up was a famous actor at the time: Edwin Booth.
(After this incident occured, Edwin's brother, John Wilkes Booth would assassinate Robert's father.)
Here's a link to some more information
I always thought that this was a fun little story that happened right in my backyard.