The stock market crash of 1929; the collapse of world trade due to the Smoot-Hawley Tariff (Hawley, it was signed by President Herbert Hoover on June 17, 1930. The act raised US tariffs on over 20,000 imported goods. The tariffs under the act, excluding duty-free imports were the second highest in United States history, exceeded by only the Tariff of 1828), government policies; bank failures and panics; and the collapse of the money supply.
I believe it was Justinian that managed to unite Rome, and expanding the Byzantine Empire.
Answer:
Delaware, Maryland, West Virginia, Kentucky, and Missouri
