David D. MacMillan is an heir to the massive Cargill fortune. His great-great grandfather W.W. Cargill founded the company in 1865. Cargill is the largest privately held corporation in the US in terms of revenue, which in 2012 was $134 billion. His father John's inherited stake was reported to be worth $1.6 billion before he passed in 2008. The family is one of the wealthiest in the country.