This tutorial will show you how to download PDFs of USGS topographic maps for free! Download any USGS topographic map, including many that were created before 1900, from https://store.usgs.gov/maplocator. This video will walk you through the process.
Coming up we will us QGIS to georeference a topographic map so it can be used for analysis.
Visit opensourceoptions.com for more content and courses