David Koch is retiring from his family’s conglomerate, Koch Industries, and is stepping down as chairman of the Americans for Prosperity Foundation.
He joined the family business in 1970. According to Forbes, the company, which was founded in 1940, had $100 billion in revenue in 2017, making it the second-largest privately held American company.
The move was announced by his brother, Charles Koch, in a letter to employees, stating that David’s health has been declining since he was hospitalized last October.
“Unfortunately, these issues have not been resolved and his health has continued to deteriorate,” Charles Koch wrote in the letter, according to The Associated Press.
Both David and Charles are major conservative donors and activists.