The outbreak of the Civil War created a continental power vacuum that allowed French forces to invade Mexico in 1862 and set up an empire ruled by a Habsburg archduke. This inflamed the ongoing power struggle between Mexico's Conservatives--landowners, the military, the Church--and Liberal supporters of social democracy, led ably by Benito Juarez. Along the southwestern border Mexico's Conservative forces made common cause with the Confederacy, while General James Carleton violently suppressed Apaches and Navajos in New Mexico and Arizona. When the Union triumph restored the continental balance of power, French forces withdrew, and Liberals consolidated a republic in Mexico.
Canada was meantime fending off a potential rupture between French-speaking Catholics in Quebec and English-speakers in Ontario. When Union victory raised the threat of American invasion, Canadian leaders pressed for a continent-wide confederation joined by a transcontinental railroad. The rollicking story of liberal ideals, political venality, and corporate corruption marked the dawn of the Gilded Age in North America.