The Southern route of the great Pacific railroad for national security, personal profit, and a side of world domination died with the fall of Rusk’s bill. That largely mooted the value of the one territory that the expansionists in Franklin Pierce’s administration both lusted after and managed to gain.
The Treaty of Guadalupe-Hidalgo set the United States-Mexico border at the Rio Grande, then a straight line west followed by a brief north-south line that intersected the Gila River. Then it ran with the river until it ran into the Colorado where another straight line went to the Pacific. By way of El Paso, a railroad from New Orleans could have, until Cass, Douglas, Shields, and Geyer made buying land out of a state for the route impossible, easily reached San Diego. Down that railway could run commerce, settlers, and slaves to a new California cotton kingdom.
Or so dreamed South Carolina railroad promoter James Gadsden. Like many Pierce appointees, Gadsden had impeccable Southern credentials. He supported the secession movement after the Armistice. But if he could not have the South out of the Union over a free California, why not enslave California? The southern section of the state had fewer Americans so a large movement of Southerners and their slaves might help facilitate California’s division. Gadsden concocted a scheme to colonize 1,200 Carolinians and Floridians and at least a few thousand slaves in the new state. California proved less than eager, but Gadsden, like many Southerners, did not give up his ambition to redress the defeats of 1850.
Pierce came into office and saw fit to snub Southern unionists, even those of his own party like Howell Cobb and Henry S. Foote, despite what they considered their heroic, not to mention successful, efforts to save the Union. Instead he gave the War Department to Jefferson Davis, who had lately taken up Calhoun’s place as the standard-bearer for the radical South. To offset Davis and his radicalism, Pierce picked Massachusetts’ Caleb Cushing for Attorney-General. People who knew Cushing from his Massachusetts days saw him as a completely unprincipled Slave Power lackey. They had a point, as he went around writing about how the nation had to crush antislavery politics. His supporters warned him that he would never take a seat in the Cabinet except by slipping in as a surprise. When the war finally came, he offered his services to Massachusetts, which refused them on the grounds of his suspect loyalty.
Gadsden’s radicalism fit right in. He learned of his appointment as minister to Mexico from Davis, who had not yet seen fit to inform Secretary of State William Marcy. That also fit with the general practice. Davis and Cushing made most of the decisions not just about internal matters in their Departments, but about national policy. Pierce could moderate a Cabinet meeting, but not control his own administration.
Pierce, or rather Davis using Pierce’s name, sent Gadsden to Mexico to fulfill his own, Davis’, and the South’s territorial ambitions. If they could not steal some more of the nation’s neighbor to the South, they would buy more. Davis’ fellow Mississippian Albert Gallatin Brown wanted Cuba, of course, but McPherson quotes his Southern ambitions as fairly typical:
I want Tamaulipas, Potosi, and one or two other Mexican States; I want them all for the same reason-for the planting and spreading of slavery.
The railroad proved the perfect excuse to bring those dreams into reality.