EXHIBIT 16.1 December 18, 2003 Securities and Exchange Commission 450 Fifth Street, N.W. Washington, DC 20549 Gentlemen: We have read Item 4 of Form 8-K dated December 18, 2003, of ACNB Corporation and are in agreement with the statements contained in paragraphs one through four. Sincerely, /s/ Stambaugh Ness, PC