The United States Civil war started in 1861. It was between the Union and the Confederacy. The Confederacy was made of states from the South. These states wanted to start their own country so they formed the Confederacy. They called their country the Confederate States of America. One of the big reasons for the war was slavery. The Confederacy wanted to keep using slaves. They said they had the right to decide this for themselves. Abraham Lincoln was president during the Civil War. He didn't want any states to leave and form their own country. He also didn't want there to be slavery. At first, the Confederacy won several battles in the war. Later, the Union took over. The Union had more men. They had better equipment too. The Union won the war. The Confederacy couldn't be its own country. Slavery was outlawed. More people could be free after the war. The Confederacy became part of the United States again. The war ended in 1865.