There are millions of maps online, but it can be difficult trying to figure out if they are truly in the public domain (which means that they are free and legal to use for commercial projects). Here are some resources that I regularly use for pulling highquality scans of maps and vintage artwork related to maps. These are free, easy to use and you can use them for anything like creating artwork for Redbubble, Teepublic, Etsy, selling copies, creating wall art whatever your art project calls for.

Links:

Raw Pixel:
https://www.rawpixel.com/
(click "Public Domain" filter on the right)

British Library:
https://www.flickr.com/photos/british...

My favorite collection is the "King's Topographical Collection":
https://www.flickr.com/photos/british...

UPDATED LINK November 2022: https://www.watercolourworld.org/coll...

New York Public Library Digital Collection:
https://digitalcollections.nypl.org/
(when searching, click the "public domain" filter)

Wikimedia Images from Geographicus:
https://commons.wikimedia.org/wiki/Ca...

If you are interested in more PUBLIC DOMAIN resources as well as deep dive artist resources for both personal and commercial projects check out my sister channel called CRAFTY STAX:
   / @craftystax