▁the ▁American ▁front ier ▁experience . ▁He ▁str essed ▁the ▁process — the ▁moving ▁front ier ▁line — and ▁the ▁impact ▁it ▁had ▁on ▁pione ers ▁going ▁through ▁the ▁process . ▁ ▁In ▁the ▁th esis , ▁the ▁front ier ▁established ▁liberty ▁by ▁re le asing ▁Americans ▁from ▁European ▁mind - sets ▁and ▁ending ▁prior ▁custom s ▁of ▁the ▁ 1 9 th ▁century . ▁ ▁The ▁Turner ▁th esis ▁came ▁under ▁attack ▁from ▁the ▁" New ▁Western ▁Histor ians " ▁after ▁ 1 9 7 0 ▁who ▁wanted ▁to ▁limit ▁western ▁history ▁to ▁the ▁western ▁states , ▁with ▁a ▁special ▁emphas is ▁on ▁the ▁ 2 0 th ▁century , ▁women ▁and ▁minor ities . ▁ ▁Be ard ian ▁School ▁The ▁Be ard ians ▁were ▁led ▁by ▁Charles ▁A . ▁Be ard ▁( 1 8 7 4 – 1 9 4 8 ), ▁who ▁wrote ▁hundreds ▁of ▁mon ograph s , ▁text books ▁and ▁interpret ive ▁studies ▁in ▁both ▁history ▁and ▁political ▁science . ▁ ▁The ▁most ▁controvers ial ▁was ▁An ▁Econom ic ▁Inter pret ation ▁of ▁the ▁Constitution ▁of ▁the ▁United ▁States ▁( 1 9 1 3 ), ▁which ▁indicated ▁that ▁the ▁found ing ▁f athers ▁who ▁wrote ▁the ▁Constitution ▁in ▁ 1 7 8 7 ▁were ▁motiv ated ▁more ▁by ▁the ▁fate ▁of ▁financial ▁invest ments ▁than ▁anything ▁ideal istic . ▁He ▁wrote : ▁ ▁The ▁over wh el ming ▁majority ▁of ▁members , ▁at ▁least ▁five - six th s , ▁were ▁immediately , ▁directly , ▁and ▁personally ▁interested