In the late 19th century, the advent of lithographic printing and the extension of rail lines collided with a near tripling of the U.S. population to create a booming market for insurance-based mapmaking. As new “fireproof” construction materials gradually appeared on the market to replace traditional wood and cast iron, insurance companies like Sanborn discovered a need to know what kinds of structures they were insuring before issuing policies. The original Sanborn maps are handsome objects in and of themselves. All colored by hand in the Sanborn home office, some maps show richly detailed and dense city streets, while others seem almost abstract in their careful register of sparser industrial tracts.

➜Mapping Out a Restoration: From the Civil War to Nixon, the Sanborn Fire Insurance Company’s maps meticulously documented buildings in thousands of cities. Today, they can be invaluable for uncovering your home’s long-lost historical details. Published by Old House Journal, 2010