Yes for agree, no for disagree. Sorry for putting this in entertainment. This just so proves that slavery was an English/Swedish thing, not a Scottish or Celtic (Dixie) thing. Swedish because it was Sweden who colonized New Jersey and Delaware and brought slavery there. All the slaveowners in the Americas were Anglo-Saxons. They were proud Union scum if you ask me.
For The Union the war was not primarily about slavery. For the south it was. States rights were a lie to gain sympathy. It is listed as one of the main reason for succession by nearly every confederate state and the others are related to it. Now looking at these five union states that had slavery. They were Missouri, Maryland, Kentucky, Delaware, and West Virginia. All of these states gave a lot of support and men to Confederacy as well as the Union. Kentucky was officially neutral and so doesn't count. West Virginia broke away from Virginia during the war to rejoin the Union. The Emancipation Proclamation freed slaves in only the confederate states. Maryland and Missouri ended slavery on their own before the war ended.
The North wanted slaves gone to win the war easier. Maryland was going to secede but its location stopped it to buy Lincoln sending the pro-Southern governor to prison. Maryland still supported the CSA. Kentucky and Missouri stayed in the Union but had confederate governments. Western Virginia broke away to form the new state of West Virginia in 1863, slavery was allowed but not a lot of people supported it. Delaware thought about secession and had some secessionist but most of the slaves where kept in Sussex County and being the first state they didn't want to be the last state to leave so the state stayed in the Union as a slave state. The war was fought over money and taxes.
President Abraham Lincoln's main motive was just to reunite the people of the United States, later it turned into freedom for most slaves so he could have their support in the war. During the Civil War Lincoln decided he didn't like how slaves in the south were being treated. At Gettysburg he proposed the Emancipation Proclamation to legally free slaves in the United States, not just the North, mind you but he didn't actually have control over the Southern states while they were split so they would just have to wait until the North won or they escaped. But Lincoln just wanted the American people to stop killing each other.
The Civil War was not about slavery, it was about taxes. The south was being heavily taxed by the north and wanted economic freedom. The Emancipation Proclamation was later introduced as a step forward towards civil rights. Arguing that the Civil War was about slavery is wrong because it was about taxes, and the five Union states with slaves is irrelevant.