federalize

verbs

unite on a federal basis or band together as a league
"The country was federated after the civil war"
federalise, federalize, federate
put under the control and authority of a federal government
federalise, federalize
is derived from
federalization
is derived from
federalization
enter into a league for a common purpose
"The republics federated to become the Soviet Union"
federalise, federalize, federate