Answer:
Seismic waves are recorded by a machine called a seismograph, which tells us about the strength and speed of the seismic waves
Explanation:
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 :)
<span>Direct election of senators to Congress occurred because of the 17th constitutional amendment.</span>
