What were the main lasting impacts of Lincoln's issuance of the Emancipation Proclamation?

Question

A) Many former slaves joined the Union army to fight for their freedom

B) The Proclamation heightened tensions between the North and the South, further escalating the conflict

C) Southern states were forced to release their slaves, significantly altering their agricultural labor system

D) The Confederacy saw a decrease in international support, as European nations viewed the proclamation as a step towards ending slavery