When designing games or just working on your own adventures and campaigns for your gaming group, accurate information really adds to the immersion level of your games. This is especially true of games and adventures set in historical time periods.
A resource that is often overlooked by many game designers and writers are mail order catalogs. Before the Internet, before Big Box Stores, even before small towns had more than general store and perhaps a small grocery, there were catalogs. The two that are most well known in the US are the Montgomery Ward & Co. Catalogue and Buyers’ Guide and the Sears Roebuck & Co. Catalogue.
Those old catalogs have a wealth of material in them far beyond just historical pricing (which is handy for creating equipment prices for games). These catalogs also give you a snap shot into the time period of the catalog including common attire, hair styles, medical options, weaponry available, beverages, food products, farm and riding animals, transportation availability, and unique things of the period including things like radioactive water and cocaine infused Coca-Cola. Flipping through these catalogs can give you a wonderful feel of the economy, industry, technology, and culture of the time period.
Replicas of these old catalogs can be purchased for very minimal costs. You can also sometimes find originals in antique stores and used book stores, but then the costs can be rather prohibitive. I found a replica small format book, the Sears, Roebuck and Co. Consumers Guide Fall 1900, at my local Goodwill and it has been an incredible resource when I am writing adventures and campaigns for my RPG gaming group. I used the catalog when prepping for a recent Wild Wild West-inspired game.
What catalogs or other old books have you found to be great references for your campaigns or game design?