Rare photo shows Mary Todd Lincoln turning the crank on an early information storage system, used to hold the Confederate Order of Battle Operations Listing. It’s a well-known fact that, given their constantly changing brigade structure and penchant for naming units after (often short-lived) commanders, even the Confederate generals were not always sure how many men they had in the field. Abraham Lincoln reportedly said that, thanks to these machines, the Union usually had a better idea than the Confederates.
Lincoln also credited his computers, as the girls who cranked the handles were called, for helping break a number of Confederate codes. “We never would have figured out how tightly they wound their paper strips around the coding pencils without the help of these fine women”, he said. Other triumphs included determining exactly which edition of Ivanhoe the Confederate government used as the basis for their unbreakable ‘book codes’.