Pfizer was founded in 1849 as Charles Pfizer and Company, a fine chemicals business. Within 50 years the company had become a leader in the American chemical business, its portfolio included a wide array of industrial and pharmacological products, anchored by citric acid, camphor, cream of tartar, borax, and iodine. By 1899, the company had offices in New York and Chicago, and contacts in the import-export business across the world. Between 1900 and 1950, the company underwent significant growth, developing deep-tank fermentation for the production of citric acid and as a result became a specialist in fermentation technology. In 1942, that expertise was put to use developing large scale deep-tank fermentation production of penicillin. A soil screening program in the late 1940's for other bacteria-fighting organisms yielded Terramycin® (oxytetracycline) the first pharmaceutical developed exclusively by Pfizer's own scientists. Following the launch of Terramycin®, in 1950, Pfizer began to organise its sales and marketing in the US and also created an international division to lead the company's expansion in international markets. During the later half of the twentieth century, Pfizer underwent explosive growth, establishing operations across the world offering products for applications to human and animal health. Substantial investment in research and development and several acquisitions, including Warner-Lambert in June 2000, have produced a portfolio of products covering many aspects of human and animal healthcare. In July 2002, Pfizer announced its intention to acquire Pharmacia and on April 16th 2003, the companies merged. In December 21, 2003, Pfizer announced it has entered into an agreement to acquire Esperion Therapeutics, a biopharmaceutical company focused on the development of high density lipoprotein (HDL) targeted therapies for the treatment of cardiovascular disease.