This coin is a unique piece from the series known as the So-Called Dollars, as cataloged by Hibler and Kappen. Specifically, it represents a denomination of $1 (One Dollar) and was produced in 1906. The coin is categorized as a 'Proof' type, which indicates that it was struck with superior craftsmanship and is likely intended for collectors rather than for circulation. As part of the So-Called Dollars series, this coin likely commemorates a specific event or theme pertinent to American history, making it of particular interest to numismatists and those collecting Americana. Despite the absence of specific details regarding minting, weight, height, width, and material, it stands out for its historical context. The coin does not have a mint mark, which means it was not associated with a particular mint facility. The mintage is listed as zero, suggesting that it may not have been officially minted or released for general circulation in the traditional sense. In summary, this 1906 So-Called Dollar Proof coin is not just a monetary instrument but a collectible artifact that captures a moment in time within the rich narrative of the United States. Its value is derived more from its historical significance and collector demand than from any physical attributes, given the unlisted dimensions and specifications.