Measuring the number of soldiers in a unit is very scattershot in history books. Generally, I see wild guesses that contradict each other depending on the source. Has there ever been a gold standard methodology for deriving the strength of a regiment at a point in time? Are those numbers in communications not entered in the O.R., because I don't see them entered by regiment (for example, in the Confederate returns after the Siege of Jackson, they are entered by division). Do you have to simply pull up the service records of each soldier to verify his service on a particular date?