What was the purpose of alexander hamilton james madison and john ray in writing the federalist papers

The Federalist papers? Its purpose was mostly to Promote the ratification of the United states constitution.

Written by as you said Alexander, james, and John, under the pseudonym or "Publuis" :) hope that helps, i don't know TO MUCH about the Federalist papers other then this :)

The executive branch is more responsible for interpreting laws !