Machine cut nails and wire nails: American production and use for dating 19th-century and early-20th-century sites

The commonly cited sources used by archaeologists for dating nails have been rendered outdated by later research. Machine cut and headed nails date from 1815 onwards, while wire nails date from 1819 onward. Historical archaeologists need to avoid the simplistic use of invention dates and patent dates and focus instead on the mass-production dates. There can be a significant amount of time between an invention and its first production, and even greater time until production figures are significantly high enough to affect the archaeological record. Usually wire nails are ascribed an 1850s beginning date, but that date is both too early and too late. While some wire nails were produced in 1819, no significant quantities were produced in the United States until the mid-1880s. Thus, we need to extend the manufacturing date back some 30 years with the caveat that the effective manufacturing date range begins in the 1880s. By examining production figures for wire nails, a model is generated for dating sites built of machine cut nails. This model is then examined using data from dozens of sites in the USA and Canada. Just as important, the model provides clues to recycling activity and access to different manufacturing sources.