Conditions in Mexico likewise deserve passing attention. For a number of years that country had been in a greatly troubled state. Years of successive revolutions had been followed by the military intervention of France, and the creation, under the protection of the French army, of a pinchbeck "empire," with the Archduke Maximilian of Austria as Emperor. The Mexican people, under the leadership of one of their greatest statesmen, Benito Juarez, never gave their allegiance to this usurping government, but maintained a more or less open resistance to it, and it was sustained for a few years only by the presence of a considerable French army. The United States of America, at this time, was engaged in its great Civil War, and was therefore unable to do more than to register a formal protest against French aggressions, which were recognized as a great violation of the Monroe Doctrine. But when, in the spring of 1865, the Civil War ended, the triumphant federal armies were moved toward the Mexican frontier, and the United States Government sent to the French Government what was practically an ultimatum, requiring it to withdraw its forces from Mexico. Napoleon III demurred, temporized, and at length offered to withdraw if the United States would recognize Maximilian as the lawful emperor of Mexico. This the United States, with great promptness, refused to do, and the French army was thereupon unconditionally withdrawn, and the capture and military execution of Maximilian soon followed, the final tragedy occurring on June 19, 1867. This left the United States with its prestige immeasurably enhanced and free to pay such attention as might be necessary to the affairs of Cuba, the only part of the western hemisphere in which European despotism was still maintained.