The correct answer is the Utah territory. This was done as a compromise on allowing new states into the union. The states in the region actually did support slavery and the vote passed even though it had been previously forbidden. This was because it was in the south where slavery was a common thing.
<span />
Part A: Working hours changed from around 14 hours a day before the 1880's to being reduced slowly down to 12, then 10, eventually moving to an 8 hour day. This change allowed for workers to to have more time to sleep and for leisure. Another change was the end of child labor. Similar to the decrease in hours, the minimum age increased over time as well moving from 10 to 16.
Part B: One strategy used by unions to achieve these goals were strikes. Workers would leave the job and picket outside of a job which shut down operations. This tactic did not work at first because there were plenty of workers to fill the jobs. However, when immigration slowed the tactic had more impact with no people to fill the jobs. Some strikes were so large they brought the attention of police forces and the government.