The ‘Siege of Petersburg – Grant’s Fourth Offensive’ orientation marker is on the west side of Halifax Road south of Flank Road at Stop One on the Petersburg National Battlefield Western Front Auto Tour. (see map)

From the ‘Siege of Petersburg – Grant’s Fourth Offensive’ marker:

Siege of Petersburg –
Grant’s Fourth Offensive

August 18-21, 1864 Battle of Weldon Railroad

Union General Ulysses S. Grant pursued a strategy of two-pronged attacks on Petersburg and the Confederate capital at Richmond. Grant fist attacked Lee’s positions around Richmond and struck again south of Petersburg. By the end of Grant’s fourth offensive, Lee’s supply lines had been bent but not broken.

From the map:

August 14-18, 1864 – Confederate forces repulse the Union atack on this line. Forces from both sides return south to support the fighting below Petersburg.

August 18-21, 1864 – As the fighting at Richmond fades Union troops swing south and sever the critical Petersburg (& Weldon) Railroad.

August 25, 1864 – Union troops tried to extend their lines along the railroad to Reams Station but were defeated and swept back by the Confederates.