Mr Kroc was so impressed by the amount of business he was doing with the McDonalds that he signed up to be their first franchisee, opening his first restaurant in Illinois, in 1955.

By 1961, he had bought them out for $2.7m.

Mr Kroc died in 1984. Well into the 1990s, the McDonalds were contesting his claim to have been the company founder.