What would you recommend for a Pulp-Era Earth world reference?  I'm talking about real-world earth from about 1920-1940.  It would be cool if it went as far back as 1880 or so, but my main focus is the Indiana Jones/between the world wars time period.

Also, it doesn't have to be a game-related book.  I know there's a lot of Call of Cthulhu and Savage Worlds stuff in that era, but I'm open to anything.

The Value of a Dollar: 1860-2014 is a book that lets you look up historical prices for stuff.

You can get it used for dirt cheap.

There is a second volume that covers 1600-1859.

He was known for his fiction, but H.G. Wells wrote a lot of nonfiction during that time. History. Politics. Social commentary.

Thank you, both.  Neither of those was on my radar.

Green Hornet (1940) is on archive.org, and it's one of those movie serials.  Green Hornet is a noir serial about a crime fighter with a secret identity, but one who is seen as a criminal by authorities, and he mingles with evildoers to get in on their secrets, to use against them.

Some of those old TV shows are on Amazon Prime as well. But I'm probably not going to keep my Prime subscription once they enact their huge price increase in a few months.

There are tons of movies as well as documentaries from the 1930s and 40s on youtube. I especially like the many reports about foreign countries and regions, such as this one about the Dutch East Indies in 1938-39:
https://www.youtube.com/watch?v=3vtOdImMfLA

Or here NYC in 1937:
https://www.youtube.com/watch?v=ZpXnEvW0XD0&t=136s

I also like reading the works by William Ralph Inge. Although he was an Anglican divine, he wrote essays about the most diverse topics imaginable, including Huxley's Brave New World, which had just been published at the time. It's also interesting to read about the great importance of eugenics back then. On the Catholic side, Inge's counterpart as an essayist was G.K. Chesterton, who is mostly known for his fiction today.

Eugenics books were very popular through the 1930s, even in the United States. It's scary how popular it was back then. I don't think America backed away from it until they learn about the horrors of Nazism.

I only know Chesterton's non-fiction (The Barbarism of Berlin, Heretics, etc.) and didn't know he ever wrote any fiction.

I have a pulp sourcebook for...Hero System(?) on my shelf. I used it when running Hollow Earth Expedition.

Quote from: Timothe on July 21, 2022, 09:17:09 AM
Eugenics books were very popular through the 1930s, even in the United States. It's scary how popular it was back then. I don't think America backed away from it until they learn about the horrors of Nazism.

I only know Chesterton's non-fiction (The Barbarism of Berlin, Heretics, etc.) and didn't know he ever wrote any fiction.

I think it was G. K. Chesterton who said, "A blind man can open his eyes, but someone with their eyes open can never be blind."

Quote from: Rhymer88 on July 21, 2022, 04:56:01 AM
On the Catholic side, Inge's counterpart as an essayist was G.K. Chesterton, who is mostly known for his fiction today.

  Depends on what circles you move in. Among Catholics of a socially conservative bent, he's a towering figure for both his fiction and non-fiction works.

Movies and novels from the pulp era also provide insights into how the people talked, although the cussing is, of course, very sanitized. I love the expression "Holy mackerel!", although I doubt it was often used in real-life. By contrast, the word "swell" was fairly common. In fact, I still remember when the Mattel toy company had the slogan "You Can Tell It's Mattel... It's Swell!" - maybe they've even revived it since then.
 

There's a ton of actual pulp fiction from the period in print as well.

I was enjoying reprints of The Spider until I realized that the villian of The Spider vs. The City Destroyer is essentially Osama bin Laden. Then it got a little too real.

Wow!  Thank you all.  I have some homework to do.

Another valuable source you might want to look into are the guidebooks of the Federal Writers' Project, which covered every state in the Union in the 1930s. Many of these guidebooks are also available as reprints.
The series is described as follows: "During the Great Depression of the 1930s thousands of writers were hired by the Works Project Administration to create hundreds of guidebooks on all of the states in the U.S. The volumes that were produced became known as the American Guide Series. This series has been described as the biggest, fastest and most original research job in the history of the world."
If you'd like to check out the guides online, you can find many of them here:
https://libguides.rowan.edu/c.php?g=248106&p=1653082
Many of the volumes link to the Hathi Trust, which has an incredible array of publications available online, including this Freshman's handbook to Cornell University, 1926-1927, which might come in handy if you are doing a Call of Cthulhu game with a university setting:
https://babel.hathitrust.org/cgi/pt?id=coo.31924125815294&view=1up&seq=1&skin=2021