Because food, materials, and money were being used for the war, so they had to even it out to spend it where they needed it most.
The economical boost of selling of cotton lead to the cotton gin being created during this period of time. Unfortunately, more cotton being produced meant more slaves being needed.
Most likely the Hebrews because they believed in the Bible while the Egyptians believed in their own polytheistic gods.
Because we dont have enough information about it.
hope this helps.
=')
