The growth of democracy was truncated by France's successful invasion of Mexico in 1862. Conservatives crowned Maximilian Hapsburg as emperor of the country, marking the nation's return to monarchy. The army which had attempted to prevent the invasion, led by Benito Juárez, started to receive US aid at the end of the American Civil War in 1865. The same year, Napoleon III declared he would no longer aid Maximilian I and urged him to abdicate. Maximilian was taken prisoner by Juárez's army, along with conservative Generals Miguel Miramón and Tomás Mejía. All three were executed in June 1867, and Juárez was reinstated as president.