Born and died in Tariffville, Connecticut. Attended Eastman Business College at Poughkeepsie, New York. Married Emma Wilson with no children.

His father was a tobacco grower and dealer. He was a dealer in leaf tobacco with stores in Kansas City and San Francisco. He returned to Tariffville about 1900. He was elected president of the Connecticut Tobacco Corporation for one term.

Mitchelson served twice on the U. S. Assay Commission. He was a member of the ANA and ANS. He was the first American elected a member of the British Numismatic Society.

He assembled an extensive collection of American coins. He willed them to the State of Connecticut. At the time of his death the value of the collection was estimated at $70,000. A secure exhibition area was constructed in Memorial Hall at the State Library Building at Hartford in 1911. One of the pallbearers at the funeral was Thomas Louis Comparette. Comparette was also a consultant to the Connecticut museum on the installation of the collection.

(Breen identified the collector as John C. Mitchelson)

obit: AJN 45 Oct 1911 p 208-209; NUM 24 Oct 1911 p 365-366 (photo p 364); ANAHist 244