Lincoln's War of Northern Aggression Fought for Manufacturing and Votes?

The Civil War continues to be a hotly debated issue in the United States. It's growing more and more clear, the war of northern aggression wasn't fought to free the slaves. Lincoln clearly had no desire to free the slaves when he took office, which you can clearly read in his inaugural address. His reasons for fighting the war, which he writes Horace Greeley, wasn't to free slaves either. Lincoln said he could care less either way on slavery, but it was his intention to keep the union together. Finally Lincoln supported the Corwin Amendment, which would have protected the institution of slavery.

So what drove Lincoln to war and uproot the Tenth Amendment, especially when the Southern States were well within their rights to secede. It should be no suprise economics and votes, at least that's something that is being presented as Zachary Likow looks at the economic motives that led to Lincoln's war of norther aggression.

Specifically, using voting patterns as representations of the Northern population’s preferences, this paper tests empirically whether the economic motivations of its manufacturing interests might have been important components of Northerners’ support of the decision to fight. The hypothesis that the North had economic motivations for keeping the South in the Union yields a specific prediction: counties with relatively large amounts of these manufacturing interests should shift their votes from Democrats to Republicans between 1860 and 1864. The reason is the following: the best way to keep the South in the Union before the Civil War was to vote for the Democrats, reducing the likelihood of secession by voting for the party more accommodating to Southern slavery interests. However, the best way to keep the South in the Union during the war was to vote for the Republicans, who were more likely to pursue the war until victory was achieved.

Using county-level census data and voting data from the 1860 and 1864 presidential elections, I find that there is a significant shift toward the Republicans associated with manufacturing employment. This shift toward the Republicans associated with manufacturing together amounts to 2.25% of voters in Northern states; that is, taking the results literally suggests that 2.25% of Northern voters shifted their votes to the Republicans out of a desire to protect their manufacturing interests by keeping the South in the Union.