Considering the last 400 years of history, was the Columbian Exchange mostly positive or negative for Europe and for the Americas, and why? Use evidence to support your answer.

Why are primary sources important when studying historical events

Is this statement true or false? before 1850, workers in american mines, mills, and factories were poorly paid, but their safety on the job was always protected by strict laws.

After ww2, the soviets began setting up what type of governments in countries closest to them