Nels Oleson is the co-proprietor of Oleson's Mercantile with his wife, Harriet Oleson. In total they have three children: Nellie, Willie and an adopted daughter named Nancy. Harriet and Nels are the perfect example of a love/hate relationship, they argue and bicker often but only on a handful of times did they take it to the next level. Soon the two separated for a bit but did manage to work out their problems and get back together.