Was an attempt to restrict a monopoly of the oil industry in the US?

Yes, the U.S. government has made several attempts to restrict monopolies in the oil industry, most notably through antitrust actions. The Sherman Antitrust Act of 1890 was a significant law aimed at curbing monopolistic practices, and it led to the breakup of Standard Oil in 1911. This landmark case established the principle that monopolies could be dismantled to promote competition and protect consumers. Subsequent regulations and enforcement actions have continued to address anti-competitive behavior in the oil sector.