Roosevelt's used pragmatism to address great depression.
Step-by-step explanation:
Pragmatism is to try new methods and theories to find solutions to a particular problem. If a theory or a method helps to solve that problem, it is accepted but if that method fails, then some other method is to be selected to solve that problem.
This was the method that was used by Roosevelt to deal with the problem of great depression. They keep trying the methods till you reach the most appropriate method to deal with the problem.