The state of the economy very much so depended on trade and mercantilism.
The Americas, Europe, and Africa all traded goods and even people. This act was mercantilism.
The triangular trade was the name of the trade routes used to transport goods.
The Middle Passage was one leg of the triangle that went from Africa to the Americas. This is when and how they would transport slave in very poor conditions. Almost 20% of the slaves on the boats did not make the journey.
Slaves would be kept, tightly packed, under the deck.
Slaves were essential to the colonization of the Americas. They were the ones who not only gathered the goods to be traded, but also built the towns. Most slaves worked on plantations, like above.
Trade and mercantilism was so important because it gave the people in the Americas the needed supplies to colonize. They traded raw goods for manufactured goods and slaves.