Not much is really known about Dunbar & Company. Edward E. Dunbar was a pioneer in every sense of the word. He left New York in December 1848, walked across the Isthmus of Panama, caught a boat to San Francisco, arriving there in February 1849. His initial business was that of a commission agent, auctioneer, storage facility and an insurer of gold dust. The first operation “went up in smoke” during the Great Fire.

In September 1850 he founded Dunbar's California Bank on famous Montgomery Street. In early 1851 Dunbar began coining operations probably with dies engraved by Albert Kuner, the only really competent engraver of the time. The machinery was thought to have come from Baldwin & Co. but as Donald Kagin properly points out in his book, Baldwin was still striking coins at that time. Since Dunbar offered to redeem Baldwin's coins at par there could very well have been an arrangement between the two firms where-by Dunbar gained access to the striking machinery for short periods of time.

Dunbar's coins assayed at $4.98 each when assayed by the mint. Kohler (State Assayer) even assayed one at $5.13, though one tends to think that it might have been “custom made” by Dunbar to insulate him from the raging controversy instigated by the banking house of James King of William.

Edward E. Dunbar, seeing that the private manufacturing of gold coin was rapidly coming to a close, came east again and organized the well known Continental Bank Note Company, which later merged with the American Bank Note Company.