1 Exhibit 24 POWER OF ATTORNEY KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears below does hereby constitute and appoint ELBERT L. THOMAS, JR., JAMES F. KEEN, CLYDE A. BILLINGS, JR., and TERESA A. ROSENGARTEN, jointly and each of them severally, his or her true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to execute and sign the Registration Statement on Form S-8 to be filed with the Securities and Exchange Commission, pursuant to the provisions of the Securities Act of 1933, by First Tennessee National Corporation ("Corporation") relating to the issuance of 1,500,000 shares of the Corporation's Common Stock, par value $0.625 per share, pursuant to the First Tennessee National Corporation 2000 Employee Stock Option Plan ("Plan") and, further, to execute and sign any and all pre-effective and post-effective amendments thereto and to file the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, or their or his or her substitute or substitutes, full power and authority to do and perform each and every act and thing requisite or necessary to be done in and about the premises, as fully to all intents and purposes as the undersigned might or could do in person, hereby ratifying and confirming all the acts that said attorneys-in-fact and agents, or any of them, or their or his or her substitute or substitutes, may lawfully do or cause to be done by virtue hereof. Signature Title Date --------- ----- ---- Ralph Horn Chairman of the Board, President October 29, 1999 - ----------------------------------- and Chief Executive Officer and a Ralph Horn Director (principal executive officer) Elbert L. Thomas, Jr. Executive Vice President and October 29, 1999 - ----------------------------------- Chief Financial Officer Elbert L. Thomas, Jr. (principal financial officer) James F. Keen Senior Vice President and October 29, 1999 - ----------------------------------- Corporate Controller (principal James F. Keen accounting officer) Robert C. Blattberg Director October 29, 1999 - ----------------------------------- Robert C. Blattberg Carlos H. Cantu Director October 29, 1999 - ----------------------------------- Carlos H. Cantu Page 1 of 2 2 George E. Cates Director October 29, 1999 - ----------------------------------- George E. Cates J. Kenneth Glass Director October 29, 1999 - ----------------------------------- J. Kenneth Glass James A. Haslam, III Director October 29, 1999 - ----------------------------------- James A. Haslam, III John C. Kelley, Jr. Director October 29, 1999 - ----------------------------------- John C. Kelley, Jr. Director October , 1999 - ----------------------------------- R. Brad Martin Joseph Orgill, III Director October 29, 1999 - ----------------------------------- Joseph Orgill, III Vicki R. Palmer Director October 29, 1999 - ----------------------------------- Vicki R. Palmer Michael D. Rose Director October 29, 1999 - ----------------------------------- Michael D. Rose William B. Sansom Director October 29, 1999 - ----------------------------------- William B. Sansom Page 2 of 2