Northern and Southern advantages and disadvantages...

Northern:
Since they created factories and many industries. Those industries would create manufactured materials such as sewing machines. People that did not own farms,so they looked for work. They went to work in factories and so the northern economy raised and its population raised too.Did not accept slavery, they thought people should be freeman.
Northern did not want annexation (for the same reasons) they did not want slave states to increase. South thought that the great and primary cause of the crisis would be that the North now had the exclusive power of controlling the Government because of north's large population (more voting more seats in the house).

Southern:
They had a better soil so a fertile land and crops were easier to grow.
Dependent on slavery because they have so much work and were used to have slaves that help them. Meaning that if slaves were illegal they would have problems growing their crops and the economy would shoot down. Southern and Democrats wanted the annexation because it would increase the number of slave states.