George Weyman opened a tobacco shop in Pittsburgh in 1822. He was the inventor of Copenhagen snuff. The company became Weyman & Bros in 1870. Since this jar just says Weyman's Snuff, it's likely to be before 1870. 
This pottery snuff jar is in AMAZING condition for it's age! I have shown it in use as a vase, but it also just makes a really great art piece and conversation piece! 
It measures approximately 6" tall, 4.5" at it's widest point. Stamped "WEYMAN'S SNUFF".
Found in an old barn in KY.