Ka cika wannan magana: A watan Nuwamba na 1842, McClernand ya auri Sarah Dunlap na Jacksonville, Illinois, abokiyar Mary Todd Lincoln. Sarah 'yar James Dunlap ce, wanda ya yi aiki a matsayin mai kula da rundunar soja a rundunar Union a lokacin yakin basasa, daga bisani aka nada shi a matsayin babban janar. Dan John da Sarah, Edward John McClernand, ya kasance sananne a matsayin janar janar na sojojin Amurka a cikin yaƙe-yaƙe na Indiya kuma daga baya a cikin
Ƙasar Filifin. Bayan mutuwar Sarah, McClernand ya auri 'yar'uwarta, Minerva Dunlap.