Kammala jumla mai zuwa: Gregg ya umurci rundunar sojan doki da suka kasance a kusa da Petersburg yayin da Sheridan ya shiga cikin Shenandoah Valley Campaign da Jubal Early. A matsayinsa na kwamandan sojan doki, Gregg ya duba ƙungiyoyin ƙungiyoyi daban-daban a cikin Siege na Petersburg. Ƙungiyar Gregg ta kasance musamman a yakin na biyu na Deep Bottom,
Yakin na biyu na tashar Ream, da kuma yakin Peebles 'Farm. Kusa da ƙarshen aikinsa, an ci gaba da shi zuwa matsayi na babban janar.