In the United States, no national assaying system was ever adopted, although the city of Baltimore did maintain its own assay office between 1814 and 1830.
Prior to the general adoption of sterling silver as the standard of purity in 1868, silver was generally obtained from the melting of coins.
Since these could vary considerably in purity, from around .750 millesimal fineness to around .900, silver known as "coin silver" varies in purity. Silver at that time was sometimes marked "COIN" or "PURE COIN", but can also be without a standard mark altogether. After the adoption of the sterling standard, pieces were marked with "STERLING", the number "925" or the notation "925/1000".
The United States also had no date marking system. Because of this, some companies within the U.S., such as Tiffany and Gorham, adopted their own date marking systems.
While American manufacturers did not apply assay marks, city marks or date marks, they did (and still do) apply a maker's mark.
For example, pieces from the Gorham company could be identified by a Lion Passant (or Lion Rampant, depending on the year), an anchor and the letter "G". The letters "T. and Co." indicated a piece manufactured by Tiffany and Company. These stamps were as unique as today's logos, and disputes often arose when one company copied another's stamp.
The difficulty with hallmarking systems other than those of the United Kingdom and Ireland is that in most cases one cannot pinpoint the manufacture to a specific year, but instead to a range of years during which the company or silversmith was in business.
Many larger companies did put out yearly catalogs, however, and these, coupled with patent dates, can often be used as a reference to narrow down the date of a specific piece. In fact, there are people who make a good income doing research on the history of specific sterling pieces.Click to go to Silver Antiques Dealers