Why were they spilt even thought there on the same content?
(The union and the confederate flag)

The scholars immediately disagreed over the causes of the war and disagreement persists today. Many maintain that the primary cause of the war was the Southern states' desire to preserve the institution of slavery. Others minimize slavery and point to other factors, such as taxation or the principle of States' Rights.

The Confederates had their own flag because they had different beliefs than the Union.

Explanation:

The Confederates wanted more freedom and the ability to have slaves, and the Union didn't, so they seceded from the Union. This succession gave them the opportunity to create a new flag, as the Union already had one (what is now referred to as the American flag). The Confederacy kept the same basic principles, but changed the flag to one that better reflected them.

interdependence is when all participating groups and individuals depend on each other. if you depend on one anothers goods, you end up trading in order to get the items you're looking for. (for ex: if i have food and you have water, we trade in order to depend on each other to live)