This study is concerned with the problem of determining the nature of impeachable offenses through an analysis of the English theory of impeachment, colonial impeachment practice, debates in the constitutional convention and the state ratifying conventions, The Federalist Papers and debates in the first Congress, In addition, the precedents established in American cases of impeachment particularly in the trials of Judge John Pickering, Justice Samuel Chase and President Andrew Johnson are examined. Materials for the study included secondary sources, congressional records, memoirs, contemporary accounts, government documents, newspapers and trial records, The thesis concludes that impeachable offenses include non-indictable behavior and exclude misconduct outside official duties and recommends some alternative method of removal for federal judges.