McKesson is based in the United States and distributes health care systems, medical supplies and pharmaceutical products. Additionally, McKesson provides extensive network infrastructure for the health care industry; also, it was an early adopter of technologies like bar-code scanning for distribution, pharmacy robotics, and RFID tags.
Founded in New York City as Charles M. Olcott in 1828 and later as Olcott, McKesson & Co. by Charles Olcott and John McKesson in 1833, the business began as an importer and wholesaler of botanical drugs. A third partner, Daniel Robbins joined the enterprise as it grew, and it was renamed McKesson & Robbins following Olcott's death in 1853.
According to wikipedia