Indefinite pronoun problem 

This sentance REALLY needs a lot of work.

"He exchanged insults with Private Hugh White, who left his post and challenged the boy, then struck him on the side of the head with his musket."

1. The pronoun "He" is undefined, and not easily deciphered from the preceding text. "He" needs to be replaced with a reference to a specific person  I don't know enough about the subject to make definitive edit...someone who is more knowledgeable needs to do this.

2. The subject of the sentence appears to be one person in the first half of the sentence, and another in the final half.  So, the latter half of the sentence needs some work  splitting it off to a separate sentence if need be.

CLARITY people!