A 1872, lauya Oliver Mowat ya zama Firayim Ministan Ontario kuma ya kasance firaminista har zuwa 1896. Ya yi gwagwarmaya don haƙƙin lardin, yana raunana ikon gwamnatin tarayya a cikin al'amuran lardin, yawanci ta hanyar roƙo mai kyau ga Kwamitin Shari'a na Privy Council. Yaƙin da ya yi da gwamnatin tarayya ya rarraba Kanada sosai, yana ba larduna iko fiye da yadda John A. Macdonald ya yi niyya. Ya ƙarfafa kuma ya faɗaɗa cibiyoyin ilimi da larduna na Ontario, ya kirkiro gundumomi a Arewacin Ontario, kuma ya yi ƙoƙari don tabbatar da cewa waɗancan sassan Arewacin Yammacin Ontario ba su kasance cikin ɓangaren Upper Canada ba (manyan yankuna a arewa da yammacin Lake Superior-Hudson, kamar yadda aka sani da gundumar Ontario) za su zama wani ɓangare na babban ɓangare na Ontario, wanda ya ƙunshi wani ɓangare na gwamnatin tarayya.
John A. Macdonald