Question

What made trade difficult for the United States in 1790. Please help me

Answer 1

Gotchu.

In the 1970's, states were printing their own money. This caused the US to have trouble paying it's debt. They didn't  have a specific state's money to use. Like now, since all the dollars and coins are the same, the US can use money from anywhere around the country to pay for things.

Hope this helps