Do you know someone who worked at the Sweetheart plastics company in Wilmington, before country music star Toby Keith sang, "Red Solo Cup, Red Solo Cup, its time to party"? Wilmington had its own red cup company with Sweetheart Plastics, which eventually was purchased by Red Solo Cup for $917.2 million in 2004. Sweetheart was founded by Russian immigrant Joseph Shapiro and his four brothers.