Born in a pre-immigration American era, baseball's championship took the name "World's Series" far before 1900. In this case, "world" refers specifically to the realm of baseball--it's not meant to be arrogant, as it might sound to modern ears. The earliest versions pitted winners from different geographic areas against each other. (In 1887, Detroit beat St. Louis 10 games to 5.)
"Oddball" card maker Sports Stars Publishing Company (SSPC) printed a bunch of sets in 1975 and 1976, including a 630-card attempt to circumvent Topps' exclusive hold on MLB players and teams. (More info thus.)
Much less controversial, this 18-card insert to SSPC's magazine reprints a distinctive (and expensive) 19th-century set made by Scrapps Tobacco, framed on a white background. Most good info on those rarities comes via auction houses. Here's one example (with scans) from Robert Edward Auctions (with whom I have no affiliation).
Card backs add a bio for each player and I like how the editor adopted some older phrasing for Mr. Rowe. (Being a lefty, I also hit "from the southerly side of the plate.")
Want to know more about 19th-century champions? See Wikipedia's article on baseball's World Series precursors.
Value: Oddballs from the 1970s rarely cost more than $5. I bought this on eBay for $3.
Fakes / reprints: Since it's already a reprint of the Scrapps die-cut set, I doubt anyone would take the trouble.