Tandem acyclic diene metathesis (ADMET) polymerization/catalytic hydrogenation has been exploited to synthesize copolymers modeling ethylene/vinyl acetate (EVA) materials. A series of four sequence-ordered ethylene-co-vinyl acetate copolymers were prepared possessing precisely defined ethylene run lengths from 18 to 26 carbons. Use of the well-defined ADMET reaction in combination with a quantitative olefin-hydrogen technique generates well-defined EVA's, all of which are semicrystalline with a linear relationship between ethylene run length and melting temperature. All polymers except that with the lowest ethylene run length are film and fiber forming.