Beyond having people make direct copies of cards by hand or using carbon paper, The Calculagraph Company manufactured a copying machine for duplicating data.

There is an accompanying picture (which I haven't copied here). Advertisement from 1906 System Magazine:

The Calculagraph<br /> Makes individual records of actual<br /> working time on separate cards<br /> which may be used interchangeably<br /> for Cost Accounting, for Pay-rolls and<br /> for a number of other purposes with-<br /> out copying or transcribing a single<br /> figure, by simply assorting the cards<br /> and adding the records directly from<br /> their faces.<br /> A card containing all the work<br /> records of one man for a week may<br /> be useful for pay-roll purposes, but it<br /> is utterly worthless for learning the<br /> cost of products, until all the items<br /> have been copied or transcribed for<br /> classification.<br /> The Calculagraph requires a large<br /> number of cards in a factory employ-<br /> ing several hundred persons, but it<br /> Saves Clerical Labor. (In one<br /> factory it saves $150.00 per week).<br /> Cards Are Cheaper Than Labor<br /> The Calculagraph Makes No<br /> Clerical Errors.<br /> Let us send you our printed matter.<br /> CALCULAGRAPH COMPANY<br /> 1414 JEWELERS BUILDING, NEW YORK CITY

According to Keith Thomas, "many of the great 19th-century historians employed professional copyists" as a means of keeping up with filing copies of their note slips under multiple subject headings.