By 1942, Morris was doing well enough to open a corrugated box plant and to buy another Baltimore enterprise, the King Folding Box Co., where he installed a corrugated sheet cutter. Morris sold corrugated partitions to major glass companies, which needed them to separate the bottles and glasses they shipped. The following year the name of his enterprise was changed to Newth Morris Box Company. In 1944, another branch was opened in Jacksonville, Florida, where the company produced cardboard anti-radar devices for World War II American troops and popcorn boxes for movie theater owners. Following Morris's purchase of Rock City Box Co. that same year, he changed the name of Newth Morris Box Co. to Rock City Box Sales Company.