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.
All states had to agree before a law was passed. Each state's vote was not equal, so there was too much disagreement. Citizens didn't always let their states know how they wanted them to vote.
People started moving towards the South in the second half of the 20th century mostly for economic reasons. Southern states had cheaper standards of living and you could find a home easier and a job. The expenses were not as high as they were in the northern countries, mostly those in the north eastern part of the US.