I te Hōngongoi 1, 1863, i whakatairangahia a Walker ki te brigadier general, a, i muri i te pakanga o Gettysburg, i whakawhiwhia ki te wehenga a Major General Henry Heth o te III Corps o te Army of Northern Virginia, i te tuatahi i whakahau i te pirihimana o Heth o mua, katahi ka pirihimana a Brigadier General James J. Archer, i muri i te whara kino o Archer. I mahi a Walker hei rangatira pirihimana i raro i a Heth kia ngaro ra ano tona waewae maui i te Pakanga o Spotsylvania Court House i te Mei 10, 1864. I uru ia ki te Pakanga o Bristoe Station i te Oketopa 14, 1863, i te Pakanga o Mine Run
I muri i tana mahi i te raorao o Shenandoah i te hotoke o te tau 1864-1864, i te Pakanga o te Maunga i mua i tana whara i te Whare Kooti o Spotsylvania.