As a History note, the Emancipation Proclamation of Abraham Lincoln was in 1863. So this photograph might have been taken exactly 100 years after the proclamation.
Slavery has a long history in human culture. Not all of it was bad. Roman slavery, for example, was mostly for prisoners, and even then still had a way out. Roman slaves could earn their freedom, and one even managed to become Consul. American slavery, however, had just about every negative connotation you could find. There was no future for these slaves, which is what makes American slavery so horrible.
It was racially motivated, the slaves were all foreign, and there was no way out of it for about 150 years. If a slave escaped, he could not blend in with the populous as a Roman slave could have. There were no other nations for him to escape to other than Canada or possibly Mexico if he played his cards right. In Rome, a slave could escape to Gaul, or simply disappear to another part of the Empire and restart his life, but in America, every black man was a slave until some began to inherit freedom. And even then, there was still no future for them.
Sometimes life was better for a slave black than a free black. Especially a domestic slave for the right household. However, if you read Fredrick Douglas' book My Bondage and My Freedom, you see that even a domestic slave that lives mere miles from the Mason-Dixon line can have the roughest life in the world.
And then there was another 50 years of debate before war broke out over it. And after that, another hundred years of racial struggle for the rights of these ex slaves' descendants to sit in the same restaurant as the previous slave owners descendants.
To put this in context, here's what happened the same year this photo was taken.
Maybe he was there
I don't know how old this guy was when the photo was taken, but it can be safe to assume that he didn't live very long as a slave. However, the hardships with slavery didn't end with the emancipation proclamation. There was still about two more years of war over the issue, and then the shit hit the fan with reconstruction (letting southern states back into the union, the formation of the KKK, voting rights taken away from southerners, uneducated blacks being voted into political positions).
I would think that a conversation with this man would be an intense experience. There's historical accounts where you get a broad view of what happened in a civilization, and then there's the personal accounts of the people in that time. These accounts include the signs of the times if you will, but this man's personal account would include each job he has worked, the women he loved, the friends he had, the times he had within this hundred year span of history.
This man saw a century of intense advancement in all aspects of society. And it can be seen in his eyes. His life is hardened. But he has lived to see this moment. The moment is over, and he is long dead now. But he made it.