Short of being the person who did the damage, people can only guess as to how it was damaged. There is no definitive answer to this question.
Could be anything, for example a kid rubbing it against a concrete step, like I just did to this one. Yes, I'm really bored.
Damaged coin, damage mind... Hey KBBPLL, look at the motto above Lincoln's head, remind you of something? Do something positive today, you'll be happy you did. Be safe.
Welcome to CT Wade. Nice avatar photo. Love the bike. As for the scratches, I used a stick pin from the bulletin board. I was bored back then. (just some humor as members already answered you question above.) LOL
Geeze, what did that cent ever do to you to deserve such treatment? Oh, right, it was struck on a copper-coated zinc planchet. Carry on, then.
Look how small the 3 in the date is compared to this one here; http://i145.photobucket.com/albums/r209/ldhair/Cent/Image_1156.jpg
Which now begs 2 questions. Where the 1913 on a different Planchet to have the copper layer cleaned away? Could this have been an attempt at a fake?
The 1913 were copper. Not just a copper layer. Something was done to your coin to give it a silver color. I don't know what.