Why was a national law against slavery needed after 1863 even though the Emancipation Proclamation had been issued?

The Emancipation Proclamation declared enslaved people free only in areas rebelling against the United States; it did not end slavery everywhere in the country. A national law was needed to abolish slavery throughout the nation, including places the proclamation did not cover. So the best choice is “The proclamation only applied to the Confederacy.”

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