An early Ben Zuckerman, when he was with Zuckerman & Kraus, which would date this suit to pre-1950. I would suggest it is perhaps 1948 or so, because is is in the New Look-Christian Dior style that was shown the previous year in Paris. The suit is made of black faille, which is a type of fabric that is slightly ribbed, and is usually silk or cotton.

This lovely suit was retailed at Bird&Speakman, Wilmington, a department store that is no longer in business, as well as Montaldo's, which was a chain of department stores opened by sisters Lillian and Nelle Montaldo in 1919. Montaldo's was famed for its personal service and very high quality clothing. Sadly it declared bankrupcy in 1995. The suit was also sold at Doop's, East Orange, NJ. Interestingly, Doop's was owned by Lillian Montaldo's husband, Raymond Doop. Doop's was also a very exclusive department store. It seems that this store too has closed.