Answer:
by using scientific methods to date key events
Explanation:
Railroads had a very large positive impact on <span>western settlement in the late 1800s</span> in the US, since this made it far easier and more effective to transport both humans and goods across large bodies of land.
So they have something to rely on
Some causes of nations joining world war 1
- Assassination of Archduke Franz Ferdinand
- Military rivalry between powerful nations
- US: the Zimmermann Telegram and the sinking of the Lusitania
- Colonies: The wish that if they fought for for their European countries they could be free, and so they join the war, making it a World War effectively
hope this helps
36' 30 is the latitude that was chosen as the dividing line between slave and free states.
