9 , ▁the ▁engine ers ▁building ▁the ▁ ▁Los ▁Angeles ▁Aqu ed uct ▁bought ▁one ▁of ▁Hol t ' s ▁Model ▁ 7 0 - 1 2 0 ▁tra ctors ▁to ▁ha ul ▁supplies ▁across ▁the ▁M oj ave ▁Des ert . ▁It ▁effort lessly ▁ha u led ▁ ▁up ▁a ▁ 1 4 % ▁grade . ▁They ▁were ▁so ▁im pressed ▁that ▁they ▁ordered ▁ 2 6 ▁more , ▁giving ▁the ▁Hol t ▁tra ctor ▁and ▁the ▁company ▁considerable ▁cred ibility ▁and ▁substantial ly ▁boost ing ▁sales . ▁ ▁Sub s idi aries ▁merged ▁▁ ▁In ▁ 1 9 1 3 , ▁Hol t ▁merged ▁its ▁various ▁companies ▁into ▁the ▁Hol t ▁Man ufact uring ▁Company , ▁with ▁a ▁combined ▁capital ▁of ▁US $ 3   mill ion . ▁The ▁merged ▁subs idi aries ▁were : ▁the ▁Stock ton ▁W heel ▁Co .; ▁the ▁Hou ser ▁and ▁H aines ▁Man ufact uring ▁Company ▁of ▁Stock ton ; ▁the ▁Aur ora ▁Engine ▁Company ▁of ▁Stock ton ; ▁the ▁Best ▁Man ufact uring ▁Company ▁of ▁San ▁Le andro ; ▁the ▁Canadian ▁Hol t ▁Company , ▁Limited ▁of ▁Cal g ary ; ▁the ▁Hol t ▁Man ufact uring ▁Company ▁of ▁Stock ton ; ▁and ▁the ▁Hol t ▁C ater p ill ar ▁Company ▁of ▁Pe oria , ▁Illinois . ▁ ▁Post - war ▁challeng es ▁▁ ▁Hol t ▁tra ctors ▁were ▁widely ▁used ▁as ▁art illery ▁tra ctors ▁during ▁W WI , ▁and ▁their ▁capabilities ▁and ▁reli ability ▁had ▁become ▁well ▁known . ▁Benjamin ▁Hol