In regards to human thought and lifestyle in any given period of time,
the interactions and concept in and of itself would be described as
culture. This is because culture refers to the norms and moors of a
given time, and how the society interacts with one another leading to a
specific type of lifestyle.
The word you are looking for is called an Indentured Servant.
It was also known as the plague and it made cites migrate to get away from it, it killed many people and there were many casualties.