Slaves were brought to work in the colonies for many reasons, although the most important reasons were to harvest crops, help families, raise children, and give birth to more slaves.
ANSWER: The first missiles to be used operationally were a series of missiles developed by Nazi Germany in World War II. Most famous of these are the V-1 flying bomb and V-2 rocket, both of which used a mechanical autopilot to keep the missile flying along a pre-chosen route.
Steam-powered ships were ran by steam and sailboats were ran by the wind.
They are both, I believe, considered megapolis's
