The subject item is best identified as Elgin National Watch Co. 15-Jewel Pocket Watch, c.1918, Late 1910s / WWI Era, Elgin National Watch Company, Elgin, Illinois, USA. Assembled in Illinois at what was then the largest watchmaking facility on Earth, Elgin watches synchronized the American railroad, workforce, and military. Produced in 1918 as the world navigated the close of the Great War, this Elgin pocket watch is a quintessential piece of American industrial horology. The robust 15-jewel movement is protected by a Keystone 'Silveroid' case, a durable cupronickel alloy specifically formulated to survive rigorous daily labor without tarnishing. While 'trench watches' were transitioning timekeeping to the wrist during WWI, the reliable pocket watch remained the definitive, essential tool for the American man.

The market for antique American pocket watches in non-precious cases is currently soft but highly liquid, driven primarily by hobbyists and entry-level collectors. Valuation for this piece is strictly determined by its configuration: an Elgin movement, a 15-jewel mid-grade specification, and a base-metal Silveroid case. Verified sales data establishes a hard ceiling of $95–$100 for running, cosmetically clean 15-jewel Silveroid examples (such as those sold by Watt's Antiques and Yesterday's Change). A baseline floor of $30–$40 exists for unserviced, unknown-jewel, or non-running examples (seen in Berner's Auction records). Because replacing a mainspring or servicing the movement costs more than the secondary market value of the watch, the current $50-$90 Fair Market Value range assumes typical, unserviced condition with decent cosmetic survival.