Parke-Davis is a subsidiary

Subsidiary

A subsidiary company, subsidiary, or daughter company is a company that is completely or partly owned and wholly controlled by another company that owns more than half of the subsidiary's stock. The subsidiary can be a company, corporation, or limited liability company. In some cases it is a...

 of the pharmaceutical company

Pharmaceutical company

The pharmaceutical industry develops, produces, and markets drugs licensed for use as medications. Pharmaceutical companies are allowed to deal in generic and/or brand medications and medical devices...

 Pfizer. Although no longer an independent corporation, it was once America's oldest and largest drug maker, and played an important role in medical history.
Parke-Davis originally was founded in Detroit, Michigan

Michigan

Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....

 by Dr. Samuel P. Duffield, a physician and pharmacist. A partnership of Dr. Duffield and Hervey Coke Parke was formed in 1866, with George S.