I remember years ago reading about a stash of Crimean War (1850s) tinned meat that was found and someone tried it and said it was OK! (I don't think I would be that brave.)
I'm sure though that we are a lot more picky than people would have been years ago, when they had no use by dates to guide them -- most would have just looked at the can to decide if it was safe. My mother used to work for HJ Heinz as an office worker, and they were often sold damaged tins at a slight discount -- which makes me shudder now.