The American Civil War, also known as the War Between the States, was a conflict that took place in the United States from 1861 to 1865. It was a war fought primarily over the issue of slavery, with the Confederate States of America, made up of 11 southern states, fighting against the Union, made up of 23 northern states.
Slavery had been a contentious issue in the United States since its founding, with many people in the north opposed to it and many in the south supporting it. However, the main cause of the Civil War was the disagreement over whether or not slavery should be allowed to expand into new territories.
Before the Civil War, the United States had been rapidly expanding westward, and new territories were being added to the Union. The question of whether or not slavery would be allowed in these new territories was a major point of contention between the north and the south.
The north, which was largely opposed to slavery, wanted to keep it out of the new territories, while the south, which relied on slave labor for its agricultural economy, wanted to be able to bring slaves into the new territories to work on plantations. This disagreement led to the passage of the Kansas-Nebraska Act in 1854, which allowed the people of each territory to decide for themselves whether or not to allow slavery.
This act, known as "popular sovereignty," was seen as a compromise, but it only served to further inflame the already heated debate over slavery. It led to a series of violent confrontations between pro-slavery and anti-slavery groups in Kansas, known as "Bleeding Kansas," and contributed to the growing tensions between the north and the south.
In the end, the main cause of the American Civil War was the disagreement over the expansion of slavery into new territories. This disagreement, along with other factors such as states' rights and regional economic differences, led to the outbreak of war in 1861 and the eventual victory of the Union in 1865. The Civil War was a significant event in American history, with far-reaching consequences that are still felt today.