ER. A.D. MDCXCCXCVIII. JOHN ADAMS, P. U.S. JAMES MCHENRY, SECRETARY OF WAR on the Pl(something something something) For those of us without Roman Numeral skills, that would be 1799; John Adams, President of the United States; James McHenry, who was the namesake of our beloved Fort McHenry in Baltimore; and I have no idea what that last line is. Next time, founding fathers, carve your slabs into stainless steel. Or better yet, mark these events digitally, so we'll be able to keep them on a thumb drive for accuracy, portability and convenience.