<span>Abolitionist John Brown leads a small group on a raid against a federal armory in Harpers Ferry, Virginia (now West Virginia), in an attempt to start an armed slave revolt and destroy the institution of slavery.</span>
Answer: A positive feedback loop occurs in nature when the product of a reaction leads to an increase in that reaction. If we look at a system in homeostasis, a positive feedback loop moves a system further away from the target of equilibrium.
