The answer is Tokyo, Japan I think
The idea that many people in the South chose to remain hired laborers was not an issue in Lincoln's eyes, because they were now part of a labor force that contributed to the new free economic policies of the nation.
The industrial revolution indeed was a great factor in the growth of population in industrialized countries. The population in industrialized countries had a sudden rise or increase due to the bigger and greater opportunities provided by the country thus, alluring more people to migrate.
Common laws became more accessible xD