Federal laws are generally applicable in the same way across all state borders. However, under constitutional laws, states are allowed to create, implement, and enforce their own laws in additional to federal laws. This is because every U.S. state is also a sovereign entity in its own right and is granted the power to create laws and regulate them according to their needs.

Another reason behind this is that each state has unique characteristics in terms of factors such as:

  • Geography and natural resources
  • Location
  • Demographics of the population
  • Historical operations of business, commerce, and industry
  • Public policies and community standards in the state