▁an ▁individual ▁to ▁serve ▁more ▁than ▁eight ▁years . ▁Although ▁nothing ▁in ▁the ▁original ▁frame ▁of ▁government ▁limited ▁how ▁many ▁president ial ▁terms ▁one ▁could ▁serve , ▁the ▁nation ' s ▁first ▁president , ▁George ▁Washington , ▁decl ined ▁to ▁run ▁for ▁a ▁third ▁term , ▁suggesting ▁that ▁two ▁terms ▁of ▁four ▁years ▁were ▁enough ▁for ▁any ▁president . ▁This ▁preced ent ▁remained ▁an ▁un written ▁rule ▁of ▁the ▁presiden cy ▁until ▁broken ▁by ▁Franklin ▁D . ▁Ro ose vel t , ▁who ▁was ▁elected ▁to ▁a ▁third ▁term ▁as ▁president ▁ 1 9 4 0 ▁and ▁in ▁ 1 9 4 4 ▁to ▁a ▁fourth . ▁ ▁The ▁Tw enty - fif th ▁Am end ment ▁( 1 9 6 7 ) ▁clar ifies ▁what ▁happens ▁upon ▁the ▁death , ▁removal , ▁or ▁res ignation ▁of ▁the ▁President ▁or ▁Vice ▁President ▁and ▁how ▁the ▁Pres iden cy ▁is ▁tempor arily ▁filled ▁if ▁the ▁President ▁becomes ▁disabled ▁and ▁cannot ▁ful fill ▁the ▁respons ib ilities ▁of ▁the ▁office . ▁It ▁su pers edes ▁the ▁ambigu ous ▁succession ▁rule ▁established ▁in ▁Article ▁II , ▁Section ▁ 1 , ▁Cla use ▁ 6 . ▁ ▁A ▁concrete ▁plan ▁of ▁succession ▁has ▁been ▁needed ▁on ▁multiple ▁occasions ▁since ▁ 1 7 8 9 . ▁ ▁However , ▁for ▁nearly ▁ 2 0 % ▁of ▁U . S . ▁history , ▁there ▁has ▁been ▁no ▁vice ▁president ▁in ▁office ▁who ▁can ▁assume ▁the ▁presiden cy . ▁ ▁The ▁Tw enty - se vent h ▁Am end ment