1981 Lincoln W/ Chain Links?

thanks T- BOP for the comment and for the def link/hint,bcuz I'm very coin illiterate. I looked for he CRH ref but didn't see that 1. any hint for me there?

From the looks of the letter stamp and double struck on the top one. It is the letter O from a normal stamp set. I don't know if what I was told a number of years ago, holds true. But it supposed to have to do with him freeing the slaves back in the day.
Being a modern counter stamper myself. I don't really do it to make any kind of statement political or other wise. But for fun as there are collectors and it is a fun reaction when somebody finds them. I slip them into the coin stream in change when buying items.
What I really find interesting is that more people getting the change some times as many as all 4 pennies will be stamped. Don't notice them.

Here are a couple of mine will have to take pic's of some others next stamping time.
They have no particular meaning
Here are a couple of others ones including a Masonic one



This is the Kennedy looking @ Lincoln one.

That would make more sense as they wouldn't want the Mason's to get one up on them. Working in a large urban school system I can see that some could interpret them another way. But for the slave analogy it should be an broken chain link.
Due to it being upright instead of the normal horizontal position I didn't recognize it out of context.
Philly you are right.