When the War Between the States began, Lincoln was far more concerned with collecting taxes than he was with ending slavery. From David Gordon at mises.org:
The Problem with Lincoln is the culmination of Tom DiLorenzo’s many years of research on Abraham Lincoln. It is a masterly summing-up and extension of his earlier classics The Real Lincoln (2002) and Lincoln Unmasked (2006). DiLorenzo is both a historian and an economist with an expert knowledge of Austrian economics and also of the public choice school. This background enables him to grasp what most other historians of the Civil War period miss, the centralizing economic plan behind Lincoln’s policies.
DiLorenzo calls attention to a vital fact that demolishes the mythological view that Lincoln’s primary motive for opposing secession in 1861 was his distaste for slavery. Precisely the opposite is true. It is well known that, in an effort to promote compromise, a constitutional amendment was proposed in Congress that forever forbade interference with slavery in states where it already existed. Lincoln referred to the proposal, the Corwin Amendment, in his first inaugural, stating that he was not opposed to the amendment, since it merely made explicit the existing constitutional arrangement regarding slavery. Of course, Lincoln was not telling the truth; nothing in the Constitution prior to the Corwin Amendment prohibited amendments to end slavery, so this new proposal did not just make the existing constitutional arrangement explicit. Readers can judge the Corwin Amendment for themselves, in a helpful set of original documents that our author includes in the book. (The Corwin Amendment is on p. 217.)