The "world" of the title is America's Midwest, and the "change" takes place from 1852 until the stock market crash of 1929. The film centers on the Nordholm family, a group of pioneers who have called the Dakotas their home. Young Muni decides to leave the home of his parents MacMahon and
O'Neill and head for Texas with a herd of cattle. Eventually he meets Kibbee, the owner of a Chicago slaughterhouse, and forms a partnership with him. Soon Muni has fallen in love with Kibbee's daughter, Astor, and the pair marry, settling down to a posh life style. By now, Muni has made a fortune
by devising a way to ship beef in refrigerated train cars. After the birth of two so...