In 1865, he founded Cargill, which by 2008 was the largest privately held corporation in the United States in terms of revenue, employing over 150,000 people in 68 countries.

He was the third of seven children of Scottish sea captain William Dick Cargill, who had emigrated to New York in the late 1830s.

[5] In 1867, he was joined by two of his younger brothers, Sam and Sylvester, in Lime Springs, Iowa, where Cargill built a grain flat house and opened a lumberyard.

[7] They had four children together:[8] In 1904, Cargill suffered from a stroke, which prompted his retirement from most day-to-day work in the company.

[3] Cargill's entire estate was to be passed on to his wife by law, but as it was going through probate, his widow Ellen also died on March 23, 1910.