Civil War: The Civil War was a conflict fought between 1861 and 1865 between the Northern states (Union) and Southern states (Confederacy) over issues including slavery, state's rights, and secession.
Emancipation Proclamation: The Emancipation Proclamation was an executive order issued by President Lincoln on January 1, 1863. It declared that all slaves in Confederate territory were to be set free, effectively changing the goals of war from preserving the Union to also ending slavery.
Union: The Union refers to the Northern states that remained loyal to the United States government during the Civil War. They opposed secession by Southern states and fought against them in order to preserve national unity.