These metal plates were recovered from the facades of pre-Civil War structures throughout Illinois. They were issued by fire insurance companies as a way for policy holders to publicly indicate that their buildings and possessions were insured against loss by fire.

The use of fire marks began in London after the Great Fire of 1666. Newly-organized fire insurance companies set up their own fire brigades, which would only put out fires in buildings bearing their company’s mark.

In the early United States, volunteer firefighting companies extinguished all blazes, regardless of whether or not a property was insured. American firemarks were thought to serve as a proof of insurance and deterrent against arson for the policy holder and as a form of advertising for the insurance company.