Grave of John Wilkes Booth

[Eva Elisabeth]

In lieu of flowers or stones, people leave pennies behind on the headstone, as if to give Lincoln the final word.

Leaving stones is a new one to me.
I've seen them on rare occasions, but never understood why they were there.
http://agraveinterest.blogspot.com/2012/...raves.html

A few other sites also indicate it is more of a Jewish custom

Jewish tradition to symbolize a visit, hence the deceased is still thought of, but Muslims are allowed to mark graves that way, too (as they aren't allowed to erect anything "structure" on graves).