Fanart of the week: https://www.deviantart.com/061603/art/Solar-Sands-fanart-830625673
Twitter: https://twitter.com/Solar_Sas

Much of the information on the midnight paintings was obtained from this website which has a few more paintings I didn't mention. If you want to learn even more I encourage people to visit it.
https://www.drseussart.com/secretandarchive

Other Sources and Useful Links:
Political cartoons - https://www.nhpr.org/post/oh-political-cartoons-he-drew-dr-seusss-surprising-side-gig#stream/0
Ads - https://www.collectorsweekly.com/articles/when-the-wild-imagination-of-dr-seuss-fueled-big-oil/
First book - https://en.wikipedia.org/wiki/And_to_Think_That_I_Saw_It_on_Mulberry_Street
https://www.theguardian.com/books/gallery/2016/jul/13/secret-midnight-paintings-of-dr-seuss-in-pictures
https://www.chicagoreader.com/chicago/art-of-dr-seuss-gallery-ted-geisel-water-tower-place/Content?oid=13952851
https://en.wikipedia.org/wiki/The_Pocket_Book_of_Boners
https://chrispearce.wordpress.com/2013/02/16/thrift-store-finds-the-pocket-book-of-boners/

Background Music: https://www.youtube.com/watch?v=RhtDllnA49A&t=391s

(From Youtube)