Complex sentence: An accurate count of the total number of individuals who served in the Confederate army is not possible due to incomplete and destroyed Confederate records; all but extremely improbable estimates of the number of Confederate soldiers range between 600,000 and 1,500,000 men.
Split into simpler sentences: An accurate count of the number of individuals who served in the Confederate army is impossible due to incomplete and destroyed Confederate records. All but extremely improbable estimates of the number of Confederate soldiers range between 600,000 and 1,500,000 men.