I agree with your comments.
Lincoln's Emancipation Proclamation applied to Southern States only, not the Northern States. He refused to extend the proclamation to the slaves in the North. Those that think the Civil War was fought for the sole purpose of freeing the slaves has a narrow PC view of history.
http://civilwar.si.edu/lincoln_first_reading.html First Reading of the Emancipation Proclamation
"In spite of vocal prodding from abolitionists, President Lincoln steadfastly refused to make the abolition of slavery a Northern goal in the early stages of the Civil War, lest doing so would alienate slaveholding border states that remained loyal to the Union. By mid-1862, however, Lincoln’s concern for enhancing the moral weight of the United States in the eyes of the world convinced him that it was time to act. In September 1862, he announced the Emancipation Proclamation, which would take effect on January 1, 1863, and declared all slaves free in those regions of the South still in rebellion."
He refused to extend the proclamation to the slaves in the North. Any general text on the war will tell you that President Lincoln carefully limited the EP to areas in active rebellion because that was how far his war powers as president extended.
The extension and protection of slavery was clearly the reason for the rebellion.
Walt