J.S. Macdonald operated in 19th century Baltimore, specializing in and manufacturing fine silver and related products. 

 

When a malleable metal is shaped by hammering from the reverse side to create a design in low relief, this is called repoussé (embossed pieces are the opposite).  This technique is ancient and has been used the world over.  Metals soft enough for use for repoussé include gold, silver, copper and alloys such as bronze. Very simple tools are employed, yet there is allowance for tremendous diversity of expression.