▁Le aven worth . ▁ ▁The ▁prison ▁was ▁described ▁by ▁P ete ▁Ear ley , ▁the ▁only ▁writer ▁at ▁that ▁time ▁who ▁had ▁ever ▁been ▁granted ▁un limited ▁access ▁to ▁the ▁prison , ▁in ▁his ▁book , ▁The ▁Hot ▁House . ▁The ▁prison ' s ▁history ▁has ▁also ▁been ▁covered ▁in ▁a ▁p ict orial ▁history ▁titled ▁U . S . ▁Pen it enti ary ▁Le aven worth ▁by ▁Kenneth ▁M . ▁La Master , ▁the ▁retired ▁Institution ▁Histor ian . ▁ ▁US P ▁Le aven worth ▁was ▁the ▁largest ▁maximum - security ▁federal ▁prison ▁in ▁the ▁United ▁States ▁from ▁ 1 9 0 3 ▁until ▁ 2 0 0 5 ▁when ▁it ▁was ▁down grad ed ▁to ▁a ▁medium - security ▁facility . ▁ ▁Design ▁US P ▁Le aven worth ▁was ▁one ▁of ▁three ▁first - gener ation ▁federal ▁pr isons ▁which ▁were ▁built ▁in ▁the ▁early ▁ 1 9 0 0 s . ▁Prior ▁to ▁its ▁construction , ▁federal ▁prisoners ▁were ▁held ▁at ▁state ▁pr isons . ▁In ▁ 1 8 9 5 , ▁Congress ▁author ized ▁the ▁construction ▁of ▁the ▁federal ▁prison ▁system . ▁ ▁The ▁other ▁two ▁were ▁Atlanta ▁and ▁Mc Ne il ▁Island ▁( although ▁Mc Ne il ▁dates ▁to ▁the ▁ 1 8 7 0 s ▁the ▁major ▁expansion ▁did ▁not ▁occur ▁until ▁the ▁early ▁ 1 9 0 0 s ). ▁ ▁The ▁prison ▁follows ▁a ▁format ▁popular ized ▁at ▁the ▁A ub urn ▁Cor re ction al ▁Fac ility ▁in ▁New ▁York ▁where ▁the ▁cell