I think this is the correct answer, but let me know if it is incorrect. People were having more children per family.
There is always the possibility that he would have, yet there are reasons as to why he would not have been to enthusiastic in supporting it too strongly. One of these reasons is that Lincoln supported joining the South and the North as fast as possible to make the Reconstruction after the Civil War more smooth and faster. If he openly supported the rights of the Black people the South would not have supported him as much as they would if he had not done so. This would go against what Lincoln wanted the United States to do to heal, somethign that Lincoln's vice president also shared with him.
Answer:
Civilization is characterized by five traits: specialized workers, complex institutions, record keeping, advanced technology, and advanced cities.