This collection consists of the American Civil War diary of Lieutenant R. Baxter Brown of the Union's Company I, 11th New Hampshire Infantry. Brown's diary notes weather conditions; his regiment's movements through Tennessee, Kentucky, Maryland, and northern Virginia; the departure of some regiments; the re-enlistment of others; and the arrival of new recruits. During July, Brown's diary entries frequently mention actions relating to Jubal Early's raid on Washington D.C. On July 13 he writes, "All business suspended and citizens called to defend the city which is under Martial law." The following day, he reports the presence of three gunboats in the Potomac River. The diary proceeds through the remainder of the year and is appended with a two-page description of his regiment's actions at the Battle of Pegram's Farm.