Mining has played an important economic role in Mexico since pre-Hispanic times. After the Spanish conquest, it attracted settlers to the arid lands of northern Mexico, displacing the borders of the Spanish dominion. In modern times, it became one of the antecedents of the Mexican Revolution when, in 1906, workers launched a major strike against the American company Cananean Consolidated Copper in the state of Sonora. The strike was repressed with violence and bloodshed, consecrating the miners as the precursors of labour struggles in the country. The Revolution itself impacted the mining industry. Article 27 of the Constitution of 1917 attributed to the nation the ownership of the land, the subsoil and its mineral wealth. Although concessions could be granted to individuals for the exploitation of resources, the State maintained its full control and stewardship of the national economy. Communal property for traditional communities was recognized in the form of the system of "ejidos", which in practice restrained private investments. In the early 1990's, the neo-liberal turnaround of the Mexican State led to a reform of Article 27 of the Constitution and the adoption of a new Agrarian Law, a new Mining Law and a new Law Governing Foreign Investments. The reform made it posible for communities organized under the system of ejidos to parcel their lands and sell portions of it, and opened up opportunities for private investments. Investors including foreign companies, could now associate themselves with ejidatorios to exploit resources without acquiring the land, or purchasing property with the consent of 100% of the ejidatorios in the first Ejido Assembly, or with 51% consent ten days later. Furthermore, the Mining Law of 1992 opened up the mining sector to foreign capital by eliminating the obligation to associate itself with national capital. It also gave companies the possibility to acquire vast concessions in national reserves. As a result, the mining sector has seen a rapid growth in Mexico.