Describe the beginning of the oil industry in Mexico. Why did Mexico cease to be a large oil producer?

Doheny's Pan American Petroleum and Sir Weetman Pearson's Mexican Eagle dominated the Mexican oil exploration. Oil was found in 1909 in "Golden Lane" near Tampico. Mexico became a major oil power, however the Mexican Constitution was changed in 1917 to say that all subsurface resources belonged to Mexico. This reversed Mexico's power in the oil industry.