- time ▁radio ▁operator , ▁assigning ▁the ▁task ▁to ▁the ▁driver . ▁After ▁extensive ▁losses ▁in ▁Africa ▁and ▁Greece , ▁the ▁British ▁realized ▁that ▁to ▁meet ▁their ▁needs ▁for ▁t anks , ▁both ▁the ▁Lee ▁and ▁the ▁Grant ▁types ▁would ▁need ▁to ▁be ▁accepted . ▁ ▁The ▁U . S . ▁military ▁used ▁the ▁" M " ▁( Model ) ▁letter ▁to ▁design ate ▁nearly ▁all ▁of ▁their ▁equipment . ▁When ▁the ▁British ▁Army ▁received ▁their ▁new ▁M 3 ▁medium ▁t anks ▁from ▁the ▁US , ▁confusion ▁immediately ▁set ▁in ▁between ▁the ▁different ▁M 3 ▁medium ▁tank ▁and ▁M 3 ▁light ▁tank . ▁The ▁British ▁Army ▁began ▁naming ▁their ▁American ▁t anks ▁after ▁American ▁military ▁figures , ▁although ▁the ▁U . S . ▁Army ▁never ▁used ▁those ▁terms ▁until ▁after ▁the ▁war . ▁M 3 ▁t anks ▁with ▁the ▁cast ▁tur ret ▁and ▁radio ▁setup ▁received ▁the ▁name ▁" General ▁Grant ", ▁while ▁the ▁original ▁M 3 s ▁were ▁called ▁" General ▁Lee ", ▁or ▁more ▁usually ▁just ▁" Gr ant " ▁and ▁" Le e ". ▁ ▁The ▁ch ass is ▁and ▁running ▁g ear ▁of ▁the ▁M 3 ▁design ▁was ▁adapted ▁by ▁the ▁Canad ians ▁for ▁their ▁Ram ▁tank . ▁The ▁h ull ▁of ▁the ▁M 3 ▁was ▁also ▁used ▁for ▁self - prop elled ▁art illery ▁as ▁with ▁the ▁original ▁design ▁of ▁the ▁M 7 ▁Pri est , ▁of ▁which ▁nearly ▁ 3 , 5 0 0 ▁were ▁built , ▁and ▁recovery ▁vehicles . ▁ ▁Oper ational ▁history ▁Of ▁the