To start, I want to say that I think Abraham Lincoln was against slavery. I just think that it is suspicious that he didn't do anything about it until it was politically and strategically advantageous for him to do so.
The biggest piece of propaganda and "history rewriting" around the Civil War is to say that the Civil War was about slavery. It was about the Federal Government vs the States. Also, to say that the evil south was just a bunch of slave traders and the north was all about civil rights, is just as false. The Civil war has been greatly painted in these colors over the years. Here are a few facts.
The definition of slavery is greatly misunderstood and is purposefully kept very vague.
The Confederate South had already outlawed human trafficking (the evil part of slavery) two years before Abe signed the Emancipation Proclamation. For the most part that is.
So first we need to understand what slavery is.
Slavery Definition:
To own another human being.
Now we need to understand ownership.
Ownership Definition:
To posses and control.
A person typically becomes a slave in one of three ways.
I will now show how each of these are legitimately practiced in the USA today.
Born into Slavery:
This is every single child who is born with a parent. The parent possesses and controls the child. The child lives with the parent (Possession). The parent decides what clothes the child will wear, what education the child will receive, what food they will eat, what medical treatment they receive and when they will sleep (Control).
To put this into perspective, what do we call it when a child is legally freed from the parent's control before the legal age? We call it emancipation, just like the Emancipation Proclamation. If they are emancipated, then weren't they first slaves? By definition (to posses and control another human being) then yes, children are "slaves". Isn't the ongoing battle between the government and parents about who controls or owns the children? The government thinks that the parents are simply the "Birthing People" and the overnight babysitters. The government wants to control the children's medical and educational decisions at the very least.
Voluntary Slavery:
Everyone who joins the military is a voluntary slave. The US government now owns you. They control where you live, what food you eat, what clothes you wear, when you sleep and whom you kill. They even give you a Government Issued serial number. They most certainly posses and control you. It is not the same thing as a "job" or career. However, you are compensated for this service, which is completely legitimate. Voluntary slavery can be a great thing and beneficial to both the slave owner and the slave.
Slave Against One's Will:
Every criminal that is detained in a prison or jail is a slave to the US Government against their will. The US Government possess them (in fact keeps them locked up) and controls their movements, healthcare and clothing. This is a legitimate instance of forced slavery. The slave forfeited his right to freedom when he chose to commit his crime and violate someone else's rights.
The Morality of Slavery:
As we can see, slavery is needed as a healthy part of society. Unfortunately, the word has been politicized and twisted into some form of evil that they refuse to define clearly. Violating a persons human rights is wrong. Steeling people from other nations or areas and forcing them into slavery is wrong. This is what the Southern Confederate States had already addressed in their constitution.
Sec. 9. (I) The importation of negroes of the African race from any foreign country other than the slaveholding States or Territories of the United States of America, is hereby forbidden; and Congress is required to pass such laws as shall effectually prevent the same.
(2) Congress shall also have power to prohibit the introduction of slaves from any State not a member of, or Territory not belonging to, this Confederacy.
So basically, what they were saying was that you could not import any more slaves, but you could keep the ones that you already owned. I think that was their attempt to start emancipating all African slaves (and their descendants) that were already in the South. Obviously, not all Southerners wanted to give up human trafficking, so this was the first step in achieving that goal. Lincoln, however leapfrogged that and simply freed all of the African descendant slaves.
It is better to clearly and properly define what slavery is (and then address it appropriately), then it is to demonize a word and criminalize any discussion about it. The Bible takes this approach to slavery. When God is laying out the laws for the new nation of Israel in the first books of the Old Testament, we see that God is protecting the slaves and granting them rights. This is the first time in civilization where we see where slaves, even though they are viewed as possessions, still have personal rights that even their owners can not violate. This is because people are made in the image of God and have God given rights. It is this Biblical view of humanity and God that protects individuals (even slaves) from the abuse of other people.