An example of unify is when the states in the United States all came back together after the Civil War as one whole country.
tr. & intr.v.u·ni·fied, u·ni·fy·ing, u·ni·fies
Origin of unifyFrench unifier, from Old French, from Late Latin ūnificāre : Latin ūnus, one; see uni– + Latin -ficāre, -fy.
(third-person singular simple present unifies, present participle unifying, simple past and past participle unified)
From Old French unifier, from Late Latin unificare.