Merck & Co. Inc. is an integrated healthcare company specializing in healthcare solutions through prescription medication, vaccines, biologic therapies, animal health, and consumer- care products. The company headquarters are in Rahway, New Jersey. The origins of the company stretch as far back as 1668, when it was founded by the Merck family in Germany. The American subsidiary of the German founding firm was established in 1891. Merck & Co. Inc. frequently features in the top 100 of the Fortune 500 list of biggest American firms by revenue.