The Cowell family built the Cowell Portland Cement Company in 1908, in the aftermath of the great San Francisco earthquake of 1906. High quality Cowell Cement was used in rebuilding the city. During operation, the plant would sometimes operate 24 hours a day, 7 days a week. Typically, the plant would shut down in November, at the beginning of the rainy season, and restart in the Spring.
For a while, the Company was its own little empire. Cowell built a town for workers and their families, complete with a firehouse, post office, boarding houses, and of course, the company store. It owned a narrow-gauge railroad, the Cowell Portland Cement Company Railroad, to bring lime from the quarry on Mount Diablo and another railroad, the Bay Point & Clayton Railroad to take cement to Bay Point for shipment.
Henry Cowell was paternalistic in his dealings with the workers and their families. Safety was a high priority, and the company was considered safe. But the company also had a reputation for managing all aspects of the plant and town. There was a curfew and strict rules in the the town, and the plant even managed the sugar in the coffee.
Cowell was no stranger to the courtroom. They were first sued in 1910 by farmers upset that the cement dust was destroying their crops. Cowell won that case, but they were sued again, and this time, the farmers were represented by John L. Garaveta. In 1935, the judge ruled that Cowell had to reduce dust by 85% or be shut down, and so, the smokestack was built. Later, Cowell was sued by the National Labor Relations Board (NLRB) over their treatment of the workers. Cowell successfully argued that they were not subject to the Federal NLRB because they operated exclusively in California. However, on appeal, the Supreme Court, in a precedent-setting ruling, said Cowell was subject to Federal rules.
Cowell was also beset by labor issues. By 1937, workers had joined the Congress of Industrial Organizations (CIO); however, Cowell refused to recognize the union. Cowell brought in the American Federation of Labor (AFL) which was a bitter rival of the CIO at that time. Labor unrest continued, and in 1946, the workers went on strike, demanding $6 per day in pay.
In 1946, Cowell announced that they would not reopen in 1947. The official reason given was that the supply of limestone was about to run out. But there is no doubt that the strike was a factor in shutting down the plant. The railroads, under competition from the trucking industry, were losing money, but trucking cement was far more expensive than their trains. So, 1946 marked the end of the Cowell Portland Cement Company.