Out From the Trenches
The Union siege lines around Petersburg were extended in a series of offensives launched westward around the city toward the South Side Railroad. In a methodical approach, Gen. Grant would use superior numbers to attack or threaten the Richmond defenses first and then send massed troops from the trenches around Petersburg out to attack the Confederate positions defending the southern and western approaches to the city.
If the Union forces were victorious in a battle resulting from one of these offensives or if the Confederates had stopped them but had not swept them from the field, the Union army would start digging in right there and extend their existing trench lines to connect with the new fort they were now building. As trenches were extended so was the Military Railroad which would be situated in the rear behind the Federal lines and forts.
If taken chronologically, one can see, with a few exceptions, that each battle occurred further west each time until the breaking point at Five Forks on April 1, 1865. These "above ground" battles punctuated the grueling and harsh routine of trench warfare at Petersburg and were the places where most of the 70,000 soldiers became casualties in the last ten months of the war.