The operations of the Massachusetts & California Co. are largely an enigma. Several $5 issues are known, but they are alloyed extensively with copper, unlike pieces made from native California gold which contains a high silver percentage. It is quite possible that the pieces were issued in the East as patterns in the manner of the known impressions from the same dies in copper and silver.
The firm, formed in Massachusetts, may have transacted its business in California, for Edgar H. Adams relates that letterheads of the Massachusetts & California Co. were discovered in California and that Frederick P. Tracy, who later became a prominent California attorney, served as the group's secretary.
Much of what is known today about the firm is derived from a May 1849 newspaper article which noted:
The Massachusetts & California Co., formed in Northampton, Mass., which originally contemplated a capital of only $6,000, has increased it to $50,000. Only a quarter of the amount, however, is to be paid in at the outset. Josiah Hayden of Haydensville is president of the company, and S.S. Wells of Haydensville, Miles G. Moies, and others, directors. Rev. F.P. Tracy goes out to California as its active agent. It is the intention of the Company to establish a private mint at California, and, with the approbation of the Government, to make coins of the same denominations as the coins of the United States, and of equal, if not a little higher, value. Mr. William H. Hayden goes out as assayer, having qualified himself for the purpose by a series of studies under Prof. Silliman, and by all the information that could be obtained at the United States Mint. Mr. Hayden is a graduate of Yale College, and is son of the president of the company. The machinery will coin about $10,000 a day. It is the intention of the Company to purchase gold dust, at the current price, and transform it into coin for circulation. Should the Government establish a Mint there, it will be worth its denominational value, or more, at the Mint. The agent and those who accompany him will go by one of the land routes.