When the armies fought around Petersburg, they were most often in quite close proximity. To guard against attacks, both sides incorporated additional obstacles to their defensive earthworks. It was believed that if the huge earthen berms and ditches were not enough to discourage advances, then other measures might dissuade offensive movements.
Pictured above are two forms. Abatis is shown in the left foreground. These were often young growth trees or cut tree tops that were defoliated and the tips of the limbs sharpened. The points were directed toward the enemy and the base buried into the ground at an angle. Often abatis was woven together to form a particularly difficult obstacle.
In the left background of the same photograph are fraise. These were larger logs with sharpened points and spaced just wide enough apart for attackers to have to stop to slide past. Of these, one Union soldier stated: "Along and in front of the enemy line bristled a heavy sharpened stakes set close together and pointing outward with an unyielding and aggressive air, as if to say 'Come and impale yourselves on us.'"
Another obstacle that was incorporated into the defenses were chevaux-de-frise (above). These devilish-looking inventions were sharpened stakes set at opposing angles and that were probed through a central log. These were often chained or wired together and had to either be chopped through or carefully rolled away, both of which slowed attackers.
Other obstacles, included sinks (latrines) between the opposing lines, and telegraph wire strung between stumps in no-man's-land. Of the sinks, Union Colonel Hazard Stevens wrote: "the enemy had placed some of their sinks in front of the abatis and stakes [fraise], so that attacking troops would have to break their lines in order to avoid falling into these filthy holes."
Telegraph wire proved especially effective, sometimes on one's own men, as a group of Maryland Union soldiers found out: "Suddenly a number of men fell flat on their faces and we thought that they had been hit by the enemy's fire. To our surprise, they hurriedly scrambled to their feet again and continued toward us. A few steps more and again they plunged to the ground. It dawned upon us then what was the cause of their strange behavior. They had tripped over the telegraph wires stretched about a foot high along the ground. The men, too, realized what was the matter and they carefully picked their way the rest of the distance, being greeted with laughter as they approached. They, however, were in no mood to enjoy the merriment."
Images courtesy of the Library of Congress.