The following websites have digitized trade catalogs; many but not all have games:

• The Strong Museum of Play, with a broad and deep range of catalogs, from the 1800s to around 1960. Hundreds of the earlier catalogs (or photocopies of them) were donated to The Strong by the AGPI.
• The Antique Toy Collectors of America
• Princeton’s Cotsen Library has early McLoughlin Bros. catalogs
• Old Wood Toys
• Parry Game Preserve, most from the 1980s and later