After WW1 the U.S. went into a Great Depression and when Franklin D. Roosevelt's was elected, his first 100 days he created many agencies to end the Great Depression.Hope that helps. :)
Taking into account the statement above "Which was a feature of the relationship between the soviet union and the united states in the era leading up to détente?"
The answer is the Arms race. Hope this helps.
The Tet Offensive, The battle of Khe Sanh, My Lai massacre