The 1905 edition of The American Card Catalog was groundbreaking as one of the earliest attempts to provide a standardized pricing guide for baseball cards from the late 19th and early 20th centuries. Published at a time when the collecting of baseball cards was just starting to gain popularity beyond children simply trading and playing with them, the 1905 ACC helped establish some structure around valuation in this nascent hobby.

Some key things to know about the 1905 edition of The American Card Catalog include:

Format: The guide was published as a small pamphlet of around 30 pages. It listed pricing information for cards from the most popular baseball sets of the 1890s through the early 1900s in a simple table format.

Pricing: Most common cards from the era were priced between 5 cents and 25 cents each. More scarce rookie cards or cards of star players could be listed up to $1. There was no standardized grading system, so condition was largely left up to the buyer and seller to determine.

Sets included: The big sets covered were 1896–1900 Pearl, 1898–1899 Mayo Cut Plug, 1899–1900 Goodwin Champions, and 1902–1905 Tobacco cards. Some rarer sets like the infamous 1909–1911 T206 set had just started production and were not comprehensively covered yet.

Research methodology: How the creators of the ACC determined their pricing is unknown, but it was likely based primarily on recent sales data from the few shops and early hobby publications dealing in these cards at the time. Standardized population reporting and census data did not yet exist.

Impact and legacy: Though crude by today’s standards, the 1905 ACC helped provide collectors structure during the early “Wild West” period of the hobby. It established some precedent that certain cards from popular sets and of star players were more valuable. Later guides would expand coverage and build on this foundation throughout the 1900s-1960s Golden Age of baseball cards.

Condition sensitivity: One limitation was the lack of formalized grading. A card listed as being worth 25 cents may have been in poor shape, affecting its true value. Buyers had to carefully examine described condition. Modern grading scales like PSA’s 1-10 system did not exist yet.

Roster changes: Players were added to the guide based on new findings of existing cards or newly discovered sets. The ACC was one of the first sources documenting the early baseball card rosters and sets before more comprehensive references emerged.

Known copies: Very few surviving copies are known to exist today, making an original 1905 ACC one of the most valuable baseball card price guides for serious vintage collectors and enthusiasts. Most that do exist show handling and age issues given their extreme fragility after more than a century.

Influence on pricing: While prices have changed drastically in the ensuing decades, the 1905 ACC established baseline valuations still referenced by collectors and experts. Certain key cards retain premiums relative to others first documented in the pioneering guide.

The 1905 edition of The American Card Catalog helped provide structure to the nascent hobby of baseball card collecting during the early 20th century. Though crude by modern standards, it served as an important first step in documenting sets, rosters and pricing during the formative “Wild West” period before more extensive guides would be produced. Extremely rare today in its original form, an intact 1905 ACC would be a prized possession in any serious vintage baseball card collection.