Rosenberg founded doughnut chain Dunkin' Donuts, opening his first shop, the Open Kettle, in Quincy, Massachusetts, in 1948.

The shop was renamed Dunkin' Donuts in 1950, and he began franchising the chain in 1955.

• He helped found the International Franchise Association in 1960.

• He left school after the eighth grade to help support his family during the Great Depression.