In 1883, who was responsible for creating the first
system of time zones in the United States?

The railroad industry

the answer to fill in the blank in this question would be the word resource, it is defined as the money, material or people (since human resource is a very valuable good) that a company or a person has at disposition (meaning they can use the resource as they see fit), to be able to complete a task or achieve a goal.  

the name of the theory is landmass theory.