"The South had more immigrants in large cities" was not a reason for the growing division between North and South after 1820, since the North had far more immigrants.
They germans used u-boats
The answer to the last question is 3. icy. The y ending sounds exactly like the y ending of funny. Good luck.
During World War I, Germany fought on the Eastern from 1914 - 1918 and the Western fronts from 1914 - 1917. Hope this helps