A volcanic eruption or extreme flooding.
Because u can travel better
Explanation:
The Democratic-Republican Party, better known at the time under various other names,[a] was an American political party founded by Thomas Jefferson and James Madison in the early 1790s that championed republicanism, political equality, and expansionism. The party became increasingly dominant after the 1800 elections as the opposing Federalist Party collapsed. The Democratic-Republicans later splintered during the 1824 presidential election. One faction of the Democratic-Republicans eventually coalesced into the modern Democratic Party, while the other faction ultimately formed the core of the Whig Party.
Over 100,000 Allied bomber crewmen were killed over Europe. More US servicemen died in the Air Corps that the Marine Corps. In World War II, British soldiers got a ration of three sheets of toilet paper a day. Americans got 22. Only 20% of the males born in the Soviet Union in 1923 survived the war.
A shortage of crops/food would have killed off the soldiers mostly, devastating the southern states. I hope this helped!
Thanks!
~Steve