Answer :

To establish Post Offices and post Roads which is one of the many examples of implied power of Congress.

Which action is an example of an implied power of Congress?

Answer

Establishing the banks of the united states

Explanation

This came as a result of the discussion by the founder who discussed the structure of the new government of America. And before made decision they were very careful about which powers each and every branch of government was to be granted

There were other implied powers like regulation of immigration and many more.