These geographic features were strengthened by a series of entrenchments, fortifications and redoubts. Advancing skirmishers found that the entrenchments were empty. The locality was photographed from the air, which revealed German gun emplacements and entrenchments. Burnside settled into entrenchments around the city, which Longstreet besieged. The mounts, forts and entrenchments are very numerous. It depicts soldiers of the 8th U.S. Colored Troops advancing against Confederate entrenchments. He decided to lure the Persians out of the defenses of entrenchments and caltrops. Thomas drove the Confederates from their entrenchments, taking about 30 prisoners. The regiment was in the vanguard of the assault on the North Taku entrenchments. A brief skirmish ensued until orders from Buckner arrived to fall back within the entrenchments. They participated in two hard days of futile assaults against Union entrenchments on Culp's Hill. The Union soldiers were also busy building their own entrenchments. As Lee's army stood in entrenchments behind Totopotomoy Creek, they were short on men. Prior to Yorktown, the corps was responsible for digging the entrenchments for the Continental Army. The soldiers met with him upon his arrival and let Drusus into their entrenchments.