From the perspective of enslaved African Americans, slavery ended before the passage of the 13th Amendment because of the Emancipation Proclamation. It is important to note that the Emancipation Proclamation did not officially end slavery, but it did provide the impetus for subsequent legislation. The Emancipation Proclamation took effect on January 1, 1863 and granted freedom to all enslaved persons in states that were in rebellion against the Union. It also inspired enslaved African Americans to leave Southern plantations in large numbers and flee toward Union lines. Union troops were forced to make provisions for these enslaved people within their ranks.
President Lincoln would argue that the Emancipation Proclamation was simply a strategic move designed to destabilize the southern states. It did not apply to border states and it was null and void if the rebellious state returned to the Union. Moreover, because the southern states had seceded, they were no longer under the authority of the federal government, thus Lincoln had no authority over them
Enslaved people played an important role in the war as soldiers (those who escaped) and as laborers in the South for the Confederacy. They served as spies for the North.
none of them are a right angle since there isn't an angle on any of those measurements that are 90 degrees.
