What did President Roosevelt's actions demonstrate?

Roosevelt's action demonstrated that when a strike gets intense enough to endanger the welfare of the public, the federal government is supposed to intervene and find a solution to the crisis.

Explanation:

There are strikes that are manageable by the local administration and then there are also strikes that are huge and complex and can only be brought to an end through the intervention of the highest authorities at the national level. Whenever a strike starts getting acute in nature, it is the responsibility of the federal government to calm it down and find a rigid solution.