B. They were the largest participants in the Great Migration.
The world's population grew yes, but not enough to multiply. Now, this is an answer, so i do have to have an answer... the answer is x1.34 roughly. it almost doubled, It didn't though.
The question has a definition word of "copperheads" which is something they want you to define. So if you rearrange the question, it can be a multiple choice question stating:
Copperheads were midwesterners who sympathized with the south and objected to
A) abolition
B) slavery
Abolition is to over throw something and start a new version of what has been overthrown
Slavery was the ownership of African Americans (seeing as this question was linked to the civil war)
Hope you can find the answer easier now (:
Answer: B. over 1 million children were orphaned
Explanation: