How did Uncle Tom's Cabin lead to increased tension between North and South?

Because, prior to the publication, most people in the North were probably not aware on how bad the conditions for slaves were in the South. They probably thought of slaves as being little more than butlers and maids. Uncle Tom's Cabin showed how terrible life was for the slave in the South. There were people working in the North for very little pay and they thought that the slave's life was not that much different than their's were. The book showed just how bad a slave's life could be.