Diaz remained president and practi cally dictator of Mexico until 1910. Dis satisfaction with his rule, however, had been steadily accumulating, and, when plans were made by his supporters in 1910 to re-elect him for another term of six years, opposition became pronounced. This was headed by Francisco I. Madero, a wealthy landowner of liberal ideas. He became a candidate against Diaz, but was arrested by the government on the eve of the election and was thus elimi nated. Diaz was re-elected for his eighth term in July 26, 1910. His rule, how ever, was brief. Madero, on his release from prison, began an active propaganda and in November headed an outbreak at Chihuahua. The movement spread rap idly, and Diaz realized that his career as ruler of Mexico was over. Following a number of successes Madero entered the City of Mexico on June 7, 1911. Diaz in the meantime had signed a treaty pro viding for his resignation. Madero was chosen president and inaugu,rated on Nov. 6. His rule, however, was short lived. Revolutions broke out in vari ous parts of the country. The most serious of these was headed by Felix Diaz, a nephew of the former president. On Feb. 19, 1913, following a sharp strug gle in the City of Mexico, having been deserted by his military commander, Victoriano Huerta, Madero was arrested and forced to resign. Four days later he was killed while being transferred from one prison to another. Huerta then be came provisional president. No sooner had he taken office, when a counter revolution, headed by Venustiano Car ranza, governor of Coahuila, broke out. The revolt spread rapidly and Huerta's position was made more difficult by the fact that the United States Government refused to recognize him as president on account of charges that he had been responsible for the death of Madero. Huerta was elected president in October, 1916. President Wilson protested against the election and demanded the elimina tion of Huerta on the condition of re suming friendly relations with Mexico. His demand was ignored and Huerta's election was declared valid. The revolu tion of Carranza continued to spread. Francisco Villa assisted Carranza and captured Juarez and other large cities. At the beginning of 1914, the Constitu tionalists, a name adopted by the Car ranza party, held nearly all the north ern States. The chief military leaders were Villa, Alvaro Obregon, and Pablo Gonzales. Their military successes con tinued. The situation of Huerta was made still more dangerous by the so called Tampico incident. American ma rines at Tampico were arrested while landing from a launch flying the Amer ican flag. President Wilson demanded an apology which was refused. This resulted in the sending of American war ships to Vera Cruz, followed by a bom bardment of the city, which was cap tured on April 21, 1914. War was averted only by the action of Argentina, Brazil, and Chile, who offered their ser vices as mediators. Delegates met at Niagara Falls on May 20 and remained in session until June 24. A provisional arrangement was drawn up, but this pro vided no practical solution for the dif ficulties. Huerta resigned the presidency in the face of continued successes of the revolutionists, on July 15. After a brief interval, Carranza became provisional supreme ruler. Villa now turned upon Carranza, whom he denounced as a traitor and in the course of months Villa became the chief power in the country. Carranza had resigned and Villa was in virtual control. Various persons acted as nominal heads of the government, al though Villa was the chief power. The Constitutionalist forces under General Obregon, however, were able to success fully oppose him and a decisive defeat was administered to Villa's army at Celaya, in April, 1915. Within a short time Villa had Iost control of all except the extreme northern districts of Mex ico. By the end of the year Carranza was again in supreme power and was recognized by the United States as head of the government.
On March 9, 1916, Villa, without warn ing, raided the town of Columbus in New Mexico, killing 18 persons, some of whom were United States soldiers who were guarding the border. President Wilson at once organized a pursuit expedition under General Pershing, which proceeded wer the border in spite of the protests of Carranza who demanded that the Ameri can troops be removed. The search for Villa was futile. In May and June oc curred other raids upon American towns and the situation became so threatening that President Wilson called out prac tically all the State Militia for service on the Mexican border. Several clashes 'ollowed between American and Mexi can troops. At Carrizal, on June 21, 1916, 12 American soldiers were killed and 24 wounded. Carranza expressed a desire for peace and asked for a confer ence. To this the President consented, and a commission consisting of three Mexicans and three Americans met in New London, Conn., on Sept. 6, 1916, and worked out a program which assured the withdrawal of the American forces from Mexico.
There now seemed promise of a period of peace. The Constitutional Convention met in February, 1917, to draft a new constitution. This contained many new and radical provisions and made espe cially stringent laws against the rights of foreigners in the country, The con stitution was adopted in 1917, when Car ranza was elected president. The inter nal affairs of the country remained in a continually troubled condition. Various revolutions broke out and at no time dur ing Carranza's rule was there complete peace. At the outbreak of the World War Mexico was the field of strong pro German propaganda. (See WORLD WAR.) Villa, who had been little heard of since the raid on Columbus in 1917, be gan raiding the border anew in 1919. Many American citizens were killed by adherents of Villa and by those of Car ranza as well. On Aug. 14, 1919, the American Government informed Mexico that immediate steps must be taken to protect American citizens. In the same month two American aviators had be come lost while flying over Mexican ter ritory and were seized and held for a ransom of $50,000. The men were re leased on the payment of the ransom. Another complication resulted from the seizure of William 0. Jenkins, Consular Agent at Pueblo, by bandits, who asked a ransom of $150,000. The American Government demanded his release, but Mexico refused to take action. The ran som was finally paid. Late in 1919 a rebellion broke out headed by Gen. Felipe Angeles. General Angeles was captured and after court-martial was shot.
Carranza's position became ever more difficult. His former military leaders, Obregon and Gonzales, became candi dates against him for the presidency in 1920. A revolution instigated by Obre gon broke out in Sonora in April, 1920. This rapidly spread over the entire coun try until Carranza was obliged to flee from the capital, accompanied by a con siderable military force. While attempt ing to reach Vera Cruz, this force was attacked and defeated by the revolution ists. Carranza fled with a small body of men, and while asleep in a small cabin at Tlaxcaltongo, was murdered on May 21, 1920. A few days later the troops of Obregon and Gonzales entered the City of Mexico in triumph. Obregon was now the most conspicuous candidate for the presidency and Gonzales professed his in tention to withdraw. Both issued state ments expressing their intention to strive to bring about friendly relations between Mexico and the United States. Adolfo de la Huerta was chosen provis ional president in May, 1920. VilIf threatened to become a disturbing factor on being refused what he considered proper recognition by the new govern ment, but after conducting a short cam paign consented, on the payment of a large sum of money and a grant of land, to refrain from any further military operations. General Obregon was elected president on Sept. 5, for six years, be-. ginning Dec. 1, 1920.