On April 17, 1863, Carson signed a partnership agreement with John Dolbeer which lasted for eighty-seven years.
By the 1890s, they owned several lumber mills, held an interest in the rail lines and in sailing vessels to insure the transport of their lumber. Dolbeer and Carson were instrumental in incorporating the Eel River and Eureka Railroad Companies. They helped build the Bucksport and Elk River Railroads and held interests in the Humboldt Northern Railroad. The major destination for lumber was San Francisco, but they shipped all over the world. To insure retail outlets Dolbeer and Carson held interests in other California lumber companies that produced finished lumber products such as molding, trim, and doors. They had diverse holdings as well, including oil fields and other non-lumber business ventures. Mr. Carson invested in many community enterprises, including the Humboldt Bay Woolen Mills and the Humboldt Shoe Factory. Mr. Carson was one of the founders of the Humboldt County Bank, the Bank of Eureka, and the Savings Bank of Humboldt County. When the local Chamber of Commerce was organized in 1883, he became a member and was appointed to its Board of Directors. At his death, his fortune was estimated to be twenty million dollars.
Mr. Carson had a reputation of treating his employees well. He paid adequate wages, reduced the working hours, and had the respect of his fellow men. Carson’s men were also very well fed and cared for. One day a fellow lumberman said to him, “Mr. Carson, you feed your men entirely too well, much better than any of the other concerns on the Bay.”
Respected by the entire community, Mr. Carson never failed to lend help to the less fortunate. All of his charities were not made public, but after his death, his will contained 116 beneficiaries, many company employees, as well as churches, hospitals and other community agencies.