Detailed historical maps of Seattle

What's going on here?

This map aligns and merges several historical fire insurance and real estate atlases into a single zoomable map, in the hope that it will be useful and edifying. The maps detail the explosive growth of Seattle between 1884 and 1908, with enough detail to show individual buildings.

Scanned images of the Sanborn maps are hosted online by the Library of Congress:

• Sanborn Fire Insurance Map, July 1884
• Sanborn Fire Insurance Map, 1888
• Sanborn Fire Insurance Map, 1893 Vol1, Vol2

Scanned images of the Baist's Real Estate Atlas of Surveys of Seattle are hosted on Paul Dorpat's site

All images are in the public domain. I'm very grateful to the Library of Congress and Paul Dorpat for hosting high resolution scans of these fascinating documents.

Who did this and how?

I did; I'm Brandon Martin-Anderson. Processing consisted of the following steps:

1. Download original high-resolution scans.
2. Trim off margins using GIMP.
3. Georeference page to a modern property line map, using QGIS3. This produced one geoTIFF per page.
4. Use QGIS3 to produce webmap tiles.