Serpentine Antiques has dated this piece to the 1860s.

There is a historical inscription to front:
Ada L. Black from her uncle D.M.N. Parker Jany 1st 1865.
This was made by Bigelow Brothers and Kennard of Boston, Massachusetts, famous makers. John Bigelow, in business in Boston since 1830, with his brothers Alanson and Abraham Bigelow, along with W. H. Kennard, were fine makers of silver and jewellery. This particular trade name was only used from 1845-1862, and changed in 1863, so this mug is dated to 1845-1862 period only. American holloware from this period is quite uncommon and rarely comes to market. The US Civil War took place 1861-1865, and most silver manufacturers were making weapons during this time, so this was likely a bespoke piece, which would have been expensive and difficult to obtain during the war. Much existing holloware was also likely melted for the war effort. European examples are much more common and available.

Size-4 5/8 wide with handle, by 3.75 inches high by 3.25 inches diameter.
Weight- quite heavy at 245 grams.
A wonderful and unusual fine quality piece of American sterling, by a great maker. With just a few marks of use, in very good condition overall.
Serpentine Antiques has dated this piece to the 1860s.
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