Why was uncle toms cabin considered a turning point in the civil war

After the election of Lincoln in 1860 on the Republican ticket, a number of slave states seceded from the Union, and the deepening secession crisis triggered the Civil War. The growing attitudes against slavery in the North, which had been reinforced by the content of Uncle Tom's Cabin, no doubt helped to secure the victory of Lincoln..

It would be an exaggeration to say that Harriet Beecher Stowe’s enormously popular novel directly caused the Civil War. Yet there's little doubt that Uncle Tom’s Cabin, by greatly influencing public opinion in the 1850s, was indeed a factor leading to the war.

In writing Uncle Tom’s Cabin, Harriett Beecher Stowe had a deliberate goal: she wanted to portray the evils of slavery in a way that would make a large part of the American public relate to the issue.