How is Harriet Beecher Stowes book Uncle Tom's Cabin blamed for starting the war?

"Uncle Tom's Cabin" by Harriet Beecher Stowe is often credited with increasing tension between abolitionists and supporters of slavery in the years leading up to the Civil War, rather than directly causing the war itself. The book's powerful portrayal of the cruelty of slavery and its impact on readers' moral conscience helped to galvanize anti-slavery sentiment in the North and provoke a stronger defense of the institution in the South, contributing to the growing divide that ultimately led to the outbreak of the Civil War.