Why did south So reluctant to give up their slaves that they were willing to start a war?

The South was deeply invested in the institution of slavery, which was central to its agrarian economy and social structure. Abolishing slavery threatened the financial stability of plantation owners and the way of life they had built around it. Additionally, many Southerners viewed slavery as a matter of states' rights and personal liberty, leading them to resist federal efforts to abolish it. This unwillingness to relinquish their slaves ultimately contributed to the outbreak of the Civil War.