The time period being referred to in the statement "antebellum period" is the period before the war broke out.
Here's why:
- The prefix "ante" in Latin means "before."
- The term "bellum" means "war" in Latin.
- Putting them together, "antebellum" refers to the time before a war, specifically in this context, the American Civil War.
Therefore, the correct answer is:
B) the period before the war broke out.