A Gettysburg authority details two critical engagements; Harry Pfanz provides the definitive account of the fighting between the Army of the Potomac and Robert E. Lee's Army of Northern Virginia at Cemetery Hill and Culp's Hill - two of the most critical engagements fought at Gettysburg on 2 and 3 July 1863. He provides detailed tactical accounts of each stage of the contest and explores the interactions between - and decisions made by - generals on both sides. In particular, he illuminates Confederate lieutenant general Richard S. Ewell's controversial decision not to attack Cemetery Hill after the initial Southern victory on 1 July.