<human>:  I have a question about the history of the US military. How many people were killed in the Civil War?
<bot>: About 620,000 people were killed in the Civil War. The war began in 1861 and ended in 1865. The war was fought between the Union and the Confederacy, which were two separate countries that fought each other. The Union was made up of the northern states, and the Confederacy was made up of the southern states. The war was fought over the issue of slavery, which was a major factor in the conflict.