Answer:
1. it happened September 17, 1862, near Sharpsburg, Maryland
2. General George B. McClellan
3. General Robert E. Lee
4. The Union (Northern) forces
5. He wanted to take pressure off the Shenandoah Valley because it was the economic strong place of the Confederacy.
6. order No.191.
7. Union (Northern) forces
8. more than 23,000
9. Replaced him with another General
10. Freedom for the slaves in the South, once the Union took back control
