The Civil War was based on a disagreement on slavery, but slavery was not the main issue. The Union opposed the South's economic system (slavery) and the South was not too happy about that so they began seceding from the Union. President Lincoln's main goal was to preserve the Union and to get the Southern states to come back. Slavery was just something that had gotten taken care of during the Civil War.
World War I
World War I lasted from July 28, 1914 – November 11, 1918. It started when the Archduke of Austria-Hungary, Franz Ferdinand, was assassinated by Serbia. It ended when Germany formally surrendered.
Willamette valley I think
It weakened it because in the Great Depression they lost all money
