Founded in New York City as Olcott & McKesson by Charles Olcott and John McKesson in 1833, the business began as an importer and wholesaler of botanical drugs.
The company successfully emerged from one of the most notorious business/accounting scandals of the 20th century-the McKesson & Robbins scandal, a watershed event that led to major changes in American auditing standards and securities regulations after being exposed in 1938.