enfranchise (v.) Look up enfranchise at Dictionary.com
early 15c., "to set free," from Old French enfranchiss-, present participle stem of enfranchir "to set or make free; grant a franchise to;" from en- "make, put in" (see en- (1)) + franc "free" (see franchise).

Meaning "to admit to membership in a state" (generally with reference to voting privileges) is from 1680s. Related: Enfranchised; enfranchisement.