Why were slaves that rebelled killed and beaten?

Because they went through many cornfields and slaughtered slave masters

Treatment of slaves varied, but the laws in slaveholding states left enslaved people without defense or recourse in any case.

Explanation:

A slave rebellion is an armed uprising by slaves. Slave rebellions have occurred in nearly all societies that practice slavery or have practiced slavery in the past. A desire for freedom and the dream of successful rebellion are often the greatest objects of song, art, and culture amongst the enslaved population.