Complex sentence: Cardwell's letter says eighty-four Americans were killed in total, including General Crabb though other accounts say only forty-one Americans were killed in the massacre itself, not including the men that died during the fighting.
Split into simpler sentences: Cardwell's letter says eighty-four Americans were killed in total, including General Crabb. Some accounts say only forty-one Americans were killed in the massacre itself, not including the men that died during the fighting.