Use of “sterling” silver (92.5% silver, 7.5% copper) came into common use in the United States in about 1850 and the word “sterling” began to be applied to goods made from it about the same time. Prior to that time most American silver was “coin silver” or 90% silver, 10% copper. The number “925”, denoting 92.5% purity, was used early on, but usually not along with the word “sterling”, although the use of both is not unheard of.
The widespread use of the number “925” is fairly recent, becoming very popular after about 1970 but mostly on jewelry. In the late 1800s and early 1900s several of the major American makers used the term “925/1000 FINE” and the word “sterling” or “sterling silver” on their goods. Examples are Mauser, Shreve, Theo. B. Starr, and Watson.
Your item is probably not French as they seldom used “sterling”. Its value depends on the maker and the weight. You can scan the “completed items” on ebay and get an idea of what similar items are bringing.
Again, a good sharp close-up of the circular mark will go a long way in helping to identify the maker.