How did foreign changes present new challenges for the United States?
(from the 1980s )

There were lots of foreign changes that presented challenges for the US. I'll give you a few examples from different time periods. The first would be when England wanted to tax the Americans in the Revolutionary period. They did this to try and restrict America's freedom. Another example would be that Russia had spies during the cold war period. This was to gain intelligence of the US war plans. Also when Germany sent the Zimmerman Telegram to Mexico during the WWII period. This was to get Mexico to launch a surprise attack on the US.

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the answer is suffrage

b) the confederacy had to pay all union war expenses.