What led to an end of slavery in the northern colonies

With the Emancipation Proclamation, the struggle between North and South transformed into a war to end slavery. Concurrent with the war's end in 1865, the thirteenth amendment to the U.S. Constitution was ratified. Slavery was declared illegal in every part of the newly restored Union.

Explanation: Many people didn't like the way the slaves got treated and some people wanted to continue slavery so that led to war.

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