It is due to i believe the rise of cotton
The thing which was a major factor that threatened the major unity in the United States in the mid-19th century was:
<h3>The Great Depression</h3>
This refers to the period around 1929 in the United States which has a profound effect on the national economy.
This led to the failure of many banks, increase in unemployment and high deflation rates which all threatened the national unity.
Read more about Great Depression here:
brainly.com/question/441267
The black death occurred during the 1340's
Answer: No other European power had established a presence in the area.
In the early 19th century, Russia had already established some colonies in Alaska, securing its presence in America. Russia was expanding East, across Siberia, and eventually started moving south, until it reached Northern California.
Americans who were involved in the sea otter business proposed some joint hunting expeditions with Russian supervisors and Native Alaskan hunters to hunt seals along the Californian coast. These expeditions allowed the Russian parties to observe large stretches of uncolonized land. This led to the conclusion that a Russian settlement could be established in California.
The only two true statements about the Democratic Party would be that "The Democrats won the Presidency in the 90's but lost control of the Congress" and "<span>In the 1850's Democrats fought over the slavery issue in California," since during this time the Democrats were mostly pro-slavery. </span>