When Ewell's corps did attack these positions on July 2 and July 3, the Union had had time to fully occupy the heights and build impregnable defenses, resulting in heavy Confederate losses. Postwar proponents of the Lost Cause movement, particularly Jubal Early, but also Maj. Gen. Isaac R. Trimble, who had been assigned to Ewell's staff during the battle, criticized him bitterly in attempts to deflect any blame for the loss of the battle on Robert E. Lee. Part of their argument was that the Union troops were completely demoralized by their defeat earlier in the day, but Ewell's men were also disorganized, and decisions such as they were propounding are far simpler to make in hindsight than in the heat of battle and fog of war.