The Democrats entered their convention deeply divided. The severe depression had made their sitting president, Grover Cleveland, wildly unpopular (the biography link here is to the White House history pages). Cleveland, the first Democratic president since the Civil War, had served two terms (1885-1889 and 1893-1897). In the early years he was popular as a reformer who opposed the corruption of big-spending Republicans in the capital, but the economic shock of 1893 eclipsed this issue.
A fiscal conservative, Cleveland sealed his fate among free silver advocates in the South and West when, in the face of economic hardship, he called a special session of Congress to further tighten .
The American Civil War began as a war over the nature and integrity of the Union. The governments of the slave states of the South, governments controlled by members of the Democratic Party, sought to secede from the Union to prevent a continuing decline in their power compared with the power of the more populous northern states. Many of these non-slave northern states had fallen under the political control of the young Republican Party of Abraham Lincoln.
By contrast with the eleven seceding southern states, the northern states sought to preserve the Union. But what began in the North as a war for the Union became, by 1863, a war for the abolition of slavery. Why did the North's war aims change within three years? For four main reasons, each of which reflected new issues coming into play: (1) because white and black abolitionists in the North brought political pressures to bear upon Lincoln to alter the Union's war aims; (2) because of a change in sentiment among northern whites, who increasingly came to understand the moral necessity of abolition; (3) because Lincoln and others came to see the military advantage of freeing southern slaves to join the fight; and, finally, (4) because African Americans themselves, both North and South, fought, voted, and argued for abolition.