Sometimes, I see a quotation in a text like this:
[F]ollowing the Civil War, departed from the Southern United States...
What does the [F]
signify? I thought that it might be for a quote which was taken mid sentence, so the editor inserted a grammatical necessity. So the original sentence would be something like:
Many freedmen, following the the Civil War, departed from the Southern United States...
I also see full words, like:
[freed slaves] departed from the Southern United States...
Am I right? Is there a style guide these conventions are following? Is this good practice?