(A) ** He didn’t want them to secede from the Union
(B) He didn’t think he had the legal right to end slavery in those states
(C) Those states were not in the Union
EXPLANATIONS BELOW
Concept note-1: -Lincoln exempted the border states from the proclamation because he didn’t want to tempt them into joining the Confederacy. Because the proclamation was a temporary war measure, it later had to be codified into law with the 13th Amendment to the Constitution.
Concept note-2: -The Emancipation Proclamation didn’t actually free all enslaved people. Since Lincoln issued the Emancipation Proclamation as a military measure, it didn’t apply to border slave states like Delaware, Maryland, Kentucky and Missouri, all of which were loyal to the Union.
Concept note-3: -“The Emancipation Proclamation freed slaves only in those states under Confederate control, ” he says. “It didn’t affect slavery in the North.” The reason is that, contrary to popular belief, Lincoln’s primary motivation wasn’t to free the slaves but to win the Civil War and reunite the Republic.
Concept note-4: -Lincoln worried that freeing the enslaved might aggravate northerners who had tired of the human and material costs of the war; he hoped it would inspire many of them. Given a noble cause, they might regain a resolve that would match that of their enemy.