From The End of the Myth (Greg Grandin, 2019) pp94-6
The Mexican citizens who suddenly found themselves inside what was now, as a result of the Treaty of Guadalupe Hidalgo, United States territory were a diverse population. They included old-line Spanish families, who could trace their land claims back generations, centuries even; their mestizo and mulatto servants and ranch hands, along with other laborers; thousands of migrants in California, prospecting for gold; and scores of indigenous peoples, including Apache, Navajo, Pueblo, Ute, Yaqui, and Tohono O’odham. Under the terms of Mexico’s constitution, most, regardless of color, were considered Mexican citizens. Now, though, they had become foreigners in their own land. They had the option of moving to a truncated Mexico. But it wasn’t clear what their status would be if they opted, as the majority did, to stay in their homes. The Supreme Court still hadn’t worked out the legal status of Native Americans within the United States’ prior boundaries, or indeed whether they could even be considered “persons within the meaning of the law.” And most of the protections and rights associated with citizenship, including the right to vote, were at that time left to the discretion of individual states, which resisted granting U.S. citizenship to many of the former Mexicans, especially if they were people of color.
They found themselves in a nation that was becoming inured to its brutality and accustomed to a unique prerogative: its ability to organize politics around the promise of constant, endless expansion. A comparison with Europe is instructive. In 1848, on the day of John Quincy Adams’s death, European workers revolted, with uprisings starting in Paris and then spreading to Vienna, Prague, Hamburg, Lyon, Milan, Palermo, Amsterdam, Budapest, Munich, Berlin, Naples, and elsewhere. Insurgents built barricades out of cobbles and waved the red flag, cutting society in two, as Alexis de Tocqueville later put it: uniting those who possessed nothing against those who possessed everything. The insurgents were defeated, but their revolt began the social-democratization of European politics, which eventually came to entail the growth of unions, the establishment of labor parties, and the extension of what came to be called social, or economic, rights, including the rights to welfare, education, health care, and pensions.
The United States too had crowded cities and hungry workers, fighting efforts to subordinate their lives to mechanical routine. But instead of waging class war upward – on aristocrats and owners — they waged race war outward, on the frontier. ’Prenticeboys didn’t head to the barricades to fight the gentry but rather joined with the gentry to go west and fight Indians and Mexicans. After which, in 1848’s November presidential election, they divided their votes between a Democratic Party Indian killer and a Whig Party Indian and Mexican killer.* The choice was between Lewis Cass, who as governor of Michigan Territory and then Jackson’s secretary of war eliminated Native Americans from the Mississippi valley, and Zachary Taylor, that Mississippi slaver whose troops in Mexico committed atrocities “sufficient to make Heaven weep,” and who earlier had hunted Seminoles with Cuban bloodhounds. During the campaign, a political cartoon circulated of Taylor in full military uniform, holding a bloody sword and sitting on a pyramid of skulls. Taylor won the election, and his “war-clan,” as one observer noted, “grew as big as the nation” itself.
In the years that followed, Jacksonian domination of the executive branch seemed near absolute. Slavery’s statesmen especially exercised monopoly control over the country’s foreign policy and war-making apparatus. The Cotton Kingdom wasn’t, in these years, moving to split from the republic but to command it, going on the offensive, committed to defend slavery in those countries where it still existed (Brazil and Cuba), protect it where it was under siege (in the southern states), and extend it where they could, as far west as possible.
* By this point, most national elections, either for the presidency or Congress, had become a contest between Whigs and Jacksonians over the “question of who could kill Indians with more fanfare,” as the historian Daniel Scallet writes in his study on the second Seminole War.