A biggie: the transcontinental railroad. Because it would economically improve wherever it was, both the North and the South competed for the railroad to be in their respective territory, evidenced by the Kansas-Nebraska Act and the Gadsen Purchase and induction of California as a free state in 1860.
In addition: people could get land cheap because it was abundant and might leave to start afresh economically.
There's other stuff I can't remember as clearly, but there's a little and I hope it helps :)
Population distribution and density patterns can be useful to understand because they help to explain how and why people migrate and develop in certain places around the world. These factors influence human migration and development and are therefore important to understand if you seek to understand how the world has developed over time and what are the forces that are driving this development.
The answwer is b but not exactly
Answer:
The greater the amount of silica in magma, the more viscous the magma is. The magma thus solidifies quicker as well.