Viagra has had a long and successful history. It was first created by pharmaceutical chemists working in Kent, England in 1989. It was originally created to treat angina, but the clinical tests failed. New tests were run after discovering that some of the volunteer participants reported increased erections after taking the drug. However, Pfizer, an American pharmaceutical company, decided to market the drug. Pfizer obtained a patent for Viagra in 1996. Later on March 27, 1998, the FDA granted approval for Viagra to be sold, becoming the first oral treatment for erectile dysfunction in the United States. Sales began shortly after and have been high ever since.