What was a major cause of regional conflicts in the United States when Kansas and Nebraska were added as new territories ?

Article iv section 2 of the constitution define the relationship between the state and federal government by stating that

Which consideration must be addressed when deciding for whom to produce? who can be most creative with the product? who has the largest resource pool? who has the greatest need? who can bring in the greatest profit?

When can a bill be sent to the president for approval?