There were several common threads that liked them together. One was trench warfare and the other was the machine gun. The gatling gun was invented during the civil war but never used.
What Are The Similarities Between Ww1 And The Civil War?
Some similarities between Ww1 and the Civil war is that the civil war was fought because of the 13 colonies and the world war was because of the assassination of the archduke franz ferdinand
Trench warfare and gatling gun