General turmoil in Mexico had existed since 1911, when dictator Porfirio Díaz was overthrown. He had governed his country on and off for 30 years and had cooperated with the exploitative schemes of foreign investors, many of whom were U.S. citizens. Mexican oil, coffee, rubber, minerals and railroads were owned overwhelmingly by non-Mexicans. A reform regime was instituted under the new president, Francisco Madero, who attempted to implement Mexican control of resources and utilities. Many American investors lost their holdings and complained bitterly to the Taft administration. In February 1913, with the out-going Republicans' apparent complicity, General Victoriano Huerta plotted the arrest and murder of Madero, and then seized office. The incoming Woodrow Wilson was offended by these undemocratic activities and refused to offer diplomatic recognition to the Huerta regime. Wilson attempted to engineer the installation of a legitimate Mexican government and stage popular elections. Huerta refused to cooperate and came under increasing pressure from an opposition movement led by Venustiano Carranza and his Constitutionalists. Wilson took no further action and followed what he called a policy of “watchful waiting” while chaos reigned in a divided Mexico. Later, an incident involving U.S. sailors and Mexican officials deepened the rift between the two nations.