What was the cause of Civil War According to Abraham Lincoln?

According to President Abraham Lincoln, the primary cause of the American Civil War was the spread of slavery to new territories. Lincoln explicitly states this when he says "this government cannot endure, permanently half slave and half free" in his "House Divided" speech delivered on June 16, 1858. He viewed the conflict as a moral struggle between the forces of freedom and slavery. This perception aligned with growing abolitionist sentiments and the rise of the anti-slavery movement. Lincoln opposed the expansion of slavery to the Western territories and considered it a violation of the principles of equality and liberty. He believed that the institution of slavery endangered the unity and future of the United States and ultimately led to the outbreak of civil war.