1. a. California was included to the Union as a free state. b. Because the capital (Washington DC) banned slavery. 2. a. The Kansas-Nebraska Act of 1854 was an act that divided the western part of Missouri into two parts; Kansas and Nebraska. b. Kansas was in between of the North (Union) and the South (Confederates). Both parties wanted Kansas to support what they support for their own interests. 3. I haven't read Uncle Tom's Cabin, sorry. 4. propaganda; and claimed as an unfair picture of slavery (not really sure about this answer)
