▁prohib it ▁in ▁the ▁territ ories ▁those ▁tw in ▁re lic s ▁of ▁bar bar ism , ▁pol yg amy ▁and ▁sla very ". ▁In ▁ 1 8 6 2 , ▁Congress ▁issued ▁the ▁Mor r ill ▁Anti - Big amy ▁Act ▁which ▁clar ified ▁that ▁the ▁practice ▁of ▁pol yg amy ▁was ▁illegal ▁in ▁all ▁US ▁territ ories . ▁The ▁L DS ▁Church ▁believed ▁that ▁their ▁religious ly ▁based ▁practice ▁of ▁pl ural ▁marriage ▁was ▁protected ▁by ▁the ▁United ▁States ▁Constitution , ▁however , ▁the ▁un anim ous ▁ 1 8 7 8 ▁Supreme ▁Court ▁decision ▁Reyn olds ▁v . ▁United ▁States ▁declared ▁that ▁pol yg amy ▁was ▁not ▁protected ▁by ▁the ▁Constitution , ▁based ▁on ▁the ▁long standing ▁legal ▁principle ▁that ▁" la ws ▁are ▁made ▁for ▁the ▁government ▁of ▁actions , ▁and ▁while ▁they ▁cannot ▁inter f ere ▁with ▁mere ▁religious ▁belief ▁and ▁opinions , ▁they ▁may ▁with ▁practices ." ▁ ▁In cre asing ly ▁har sh ▁anti - pol yg amy ▁legisl ation ▁in ▁the ▁US ▁led ▁some ▁M orm ons ▁to ▁em igr ate ▁to ▁Canada ▁and ▁Mexico . ▁In ▁ 1 8 9 0 , ▁L DS ▁Church ▁president ▁Wil ford ▁Wood ru ff ▁issued ▁a ▁public ▁declaration ▁( the ▁Man if esto ) ▁announ cing ▁that ▁the ▁L DS ▁Church ▁had ▁dis cont in ued ▁new ▁pl ural ▁mar ri ages . ▁Anti - M orm on ▁sentiment ▁w an ed , ▁as ▁did ▁opposition ▁to ▁state hood ▁for ▁Ut ah . ▁The ▁Sm oot ▁H