I have also discussed in more than one post whether the Compromise of 1850 was a good thing or bad thing. This breaks down, as I see it, into essentially two counterfactual questions. Would war have erupted in 1850 or 1851 if the Compromise had failed? And, if so, would the North have won?
In his new book on the Compromise, Fergus M. Bordewich answers the first question in the affirmative, the second in the negative. He therefore concludes that "the Compromise must be judged a success." (He qualifies this with the proviso, "albeit a temporary one," but that's another story. Millard and the other men who crafted the Compromise in 1850 had no way of predicting, for example, Bloody Kansas.)
As to the first issue, Bordewich has no doubt that "[f]ailure . . . meant war." As I have argued before, he is convinced that the first shots would have been fired in Santa Fe. But even a desultory border scrimmage between Texas and U.S. forces or New Mexican militia would have drawn in volunteers from other southern states and widened into a general war:
Failure would have meant war, with its first shots fired at Santa Fe instead of Fort Sumter. Even if Texas had suffered an initial defeat, southerners were ready to rush to her aid. . . . Large numbers of southerners had come to accept secession as politically reasonable, economically rational, and morally justified.
Intertwined with this issue is Bordewich's response to the second question. The North would have lost, he maintains, primarily because it would not have put up a serious fight:
The North, if it had any stomach for war at all in 1850, would likely have lost. . . . [F]ew northerners . . . were prepared to fight a war for the Union, much less to end slavery. There was nothing in the North to compare with the flaming war fever that was epidemic in the newspapers of the South, and the fiery letters that war-hungry men from South Carolina to Mississippi sent to the leaders of Texas, begging for a chance to fight for slavery.
During the 1850s northern industrial resources grew by leaps and bounds. Although this may also have contributed to the Union's victory a decade, but the crucial difference was "will":
During the decade that was purchased by the Compromise of 1850, the North's advantages in population, industrial production, and transportation steadily grew. . . . But it took more to win the Civil War than factory output: it required will. In the course of the 1850s, as slavery continued to gnaw at the nation's political vitals [other southern outrages omitted]. white Americans [in the North] increasingly understood that the erosion of their own rights was tied to the fate of enslaved blacks . . ..
Finally, Bordewich evocatively describes what might have happened if northerners like President Fillmore had taken the moral high road in 1850 and lost:
Had secession taken place peacefully in 1850, the South would have set a precedent that in time might well have splintered what remained of the United States still further. The United States might then have evolved into a congeries of states - a Pacific Republic, a federation of New England, another of the upper Midwest - competitive with one another, vulnerable to foreign interference, and perhaps chronically at war. A truncated United States would never have become a globe-striding power, or a beacon of liberty for the rest of the world, but more likely a second-tier state like Germany or France. . . . That none of this happened, we owe to the compromisers of 1850.