The flag of New York City
I recreated the New York City flag out of public domain images from New York Public Library's Digital Collections.
The blue area on the left is a map of Inwood; the orange on the right is bookcloth; the middle white swath is a blank vellum page; all the bits and pieces that make up the seal are cut out of various prints. A handful of things came from NYPL's extensive menu collection.
(I tried to find an illustration of a Native American from a tribe that came from the NYC area; I chose a Mohawk person, although of course who knows how accurate those old prints are, many times the illustrator just added a few things to a basic template, assuming no one would be the wiser.)