Someone plz help me giving brainliest

Why was it difficult fpr unions to succeed in the 1800s

In what primary way did the goals for us intervention in europe differ from those of the soviet union

Ineed asap! ! what is the name of the system in which each branch of the u.s government can limit the actions of the other branches? a. perpetual union b. division of powers c. cooperative federalism d. checks and balances