In the decades before the civil war, between one-fifth and one-third of all slave marriages were broken up via

In the decades before the Civil War, between one-fifth and one-third of all slave marriages were broken up via sale or forced migration.

Explanation:

In the south of America the concept of family played a major role in everyday lives of confined African Americans. As a Family it provides slaves with individuality apart from their master, associations with other slaves, and it has made them to preserve their traditions and beliefs of their own communities.

This family as an entity also provided as a system for sharing; what is happening around them, it has taught them the resistance tactics, and it will give advice of all kinds. Most of the slave marriages were remains in existence for many years, even though the danger of sale always loomed them. The more and more interstate sale in the early part of the nineteenth century was the main reason for marriages ending of thousands of slave families.  

c. businesses/firms & government