Cozen O'Connor P.C. is a large U.S. law firm based in Center City Philadelphia, Pennsylvania. The firm was ranked 99th on the AmLaw 100 Survey in 2011, ranked 114th on the AmLaw 200 Survey in 2008, and ranked 89th on the National Law Journal's list of the 250 Largest American Law Firms in 2007. Although it is one of the younger large firms in the United States, it has pursued a strategy of aggressive growth, and has expanded to 23 offices employing over 500 lawyers. Cozen O'Connor is one of many large law firms providing counsel to the detainees at the Guantanamo Bay detention camp.