▁of ▁energy ▁in ▁the ▁United ▁States . ▁The ▁United ▁States ▁influ ences ▁world ▁oil ▁res erves ▁for ▁both ▁growth ▁and ▁development . ▁ ▁As ▁the ▁ 2 0 th ▁century ▁progress ed , ▁pet role um ▁gained ▁increasing ▁importance ▁by ▁providing ▁he ating ▁and ▁electric ity ▁to ▁the ▁commercial ▁and ▁industrial ▁se ctors . ▁O il ▁was ▁also ▁used ▁in ▁transport ation ; ▁first ▁for ▁rail ro ads ▁and ▁later ▁for ▁motor ▁vehicles . ▁ ▁As ▁autom ob iles ▁became ▁more ▁afford able , ▁demand ▁for ▁oil ▁quickly ▁rose . ▁ ▁Since ▁the ▁rise ▁of ▁the ▁autom obile ▁industry , ▁oil ▁price , ▁demand , ▁and ▁production ▁have ▁all ▁increased ▁as ▁well . ▁Between ▁ 1 9 0 0 ▁and ▁ 1 9 8 0 , ▁fuel ▁was ▁directly ▁correl ated ▁with ▁G ross ▁National ▁Product ▁( GN P ). ▁Furthermore , ▁oil ▁shock s ▁have ▁often ▁coinc ided ▁with ▁re cess ions , ▁and ▁the ▁government ▁has ▁respond ed ▁to ▁oil ▁shock s ▁in ▁several ▁ways . ▁In ▁the ▁ 1 9 2 0 s , ▁oil ▁prices ▁were ▁pe aking ▁and ▁many ▁comment ators ▁believed ▁that ▁oil ▁supplies ▁were ▁running ▁out . ▁Congress ▁was ▁confront ed ▁by ▁requests ▁to ▁augment ▁supplies , ▁so ▁a ▁gener ous ▁de ple tion ▁allow ance ▁was ▁en act ed ▁for ▁produ cers ▁in ▁ 1 9 2 6 , ▁which ▁increased ▁invest ment ▁returns ▁substantial ly . ▁This ▁change ▁induced ▁additional ▁expl oration ▁activity , ▁and ▁subsequently ▁the ▁discovery ▁of ▁large ▁new ▁oil ▁res er