What to the slave is the fourth of July?

I think Douglass spends time talking about the points that don't need to be argued because everyone knows the points but they are looked over by many. The slaves did not feel free and did not have the freedom as everyone else. They were pushed around by everyone. Douglass is talking about the points because even though everyone is supposed to be treated as equals the slaves were not. The fourth of July to them is just reminding them of how they used to be treated.