 Convenient rail links with the nearby US gave local entrepreneurs from seven wealthy merchant families a competitive advantage over more distant cities.New federal laws in 1884 and 1887 allowed corporations to be more flexible.By the 1920s, American Smelting and Refining Company (ASARCO), an American firm controlled by the Guggenheim family, had invested over 20 million pesos and employed nearly 2,000 workers smelting copper and making wire to meet the demand for electrical wiring in the US and Mexico.