From U.S. Senator Tom Cotton, an intimate and inspiring portrait of Arlington National Cemetery's Old Guard, the official ceremonial unit of the U.S. Army and Americas oldest infantry unit, dating to 1784: part history of the Old Guard, part memoir of Senator Cotton's time as a platoon leader in the unit, part meditation on service, tradition, and patriotism. It is the most sacred square mile in America. A city of the dead-more than 400,000 inhabitants and growing with each passing week. On 624 sloping acres, across a river from the nation's capital, lie generations of heroes in a place called Arlington. The hallowed grounds contain presidents and privates, some of the most famous names in military and political history-Supreme Court justices, five-star generals, and war heroes-as well as liberated slaves, and the bodies of soldiers known only to God. For sixteen months, in between combat tours in Iraq and Afghanistan, Tom Cotton, United States Senator from Arkansas, served as a platoon leader for the 3rd U.S. Infantry Regiment at Arlington. Known as "The Old Guard," these soldiers perform military-honor funerals for our fallen and welcome presidents and kings to our nation's capital, putting in countless hours behind the scenes in their quest for perfection to honor. Membership in The Old Guard is a high honor for a U.S. soldier, and its soldiers serve to remind Americans that tradition, integrity, and patriotism still matter. Sacred Duty is both a history of the 3rd Infantry Regiment-the oldest active-duty regiment in the Army-and a personal reflection on honor, ritual, and service, from one of our most respected public figures. It is also a meditation on the value of service to one's country-and on those who have paid the ultimate price for our freedom. Includes approximately 25 photos.