After graduating from Harvard Law School (1872), Bonaparte began the practice of law in Baltimore in 1874. He was active in organizations advocating municipal and civil service reform, which gained him the admiration of Roosevelt, who was then a member of the U.S. Civil Service Commission. Upon Roosevelt's accession to the presidency, Bonaparte served as secretary of the navy (1905–06) and as attorney general (1906–09). In the latter post he established the Federal Bureau of Investigation (originally the Bureau of Investigation) and prosecuted numerous antitrust suits, most notably that which resulted in the dissolution in 1911 of the American Tobacco Company.