Members of a President’s Day panel talked about the presidential biographies they wrote for Times Books' American Presidents series. Mr. Schlesinger, the general editor of the series, moderated the panel. Mr. Phillips wrote William McKinley. Mr. Dean is the author of Warren G. Harding. Mr. Trefousse wrote Rutherford B. Hayes. Mr. Seigenthaler is the author of James K. Polk. Following prepared remarks, the panelists responded to questions from the audience.