Rose and Jim Totino had been running a pizza restaurant in St. Paul, Minn., for a little over a decade when they decided to launch a frozen-pizza operation. The concept was a huge success, and Pillsbury purchased the Totino’s brand in 1975 for $20 million. Another frozen pizza pioneer, Ellio’s, was introduced in 1963 with a unique rectangular shape—just the right size to fit inside a toaster oven, which by then was a staple appliance in many American kitchens.