As Hardee's Corps and Stewart's Army of Mississippi assailed Thomas's Army of the Cumberland north of Atlanta, the rest of Sherman's army group continued to inch forward to the east and northeast of Atlanta. Schofield's Army of the Ohio and two divisions of Oliver O. Howard's Fourth Corps worked through tangled vegetation in their effort to link Thomas with McPherson's Army of the Tennessee. They made limited progress, essentially coming up to the developing Confederate position known as the Peach Tree Creek Line (which faced north) and the Confederate Outer Line (which faced east). Elements of Howard's and Schofield's commands skirmished with troops from Benjamin F. Cheatham's Corps (formerly commanded by Hood), which was responsible for holing the far right of the Peach Tree Creek Line and all of the Outer Line. But a gap continued to exist between Howard and John Newton's division. Fortunately for the Federals, the Confederates never became aware of this potentially dangerous hole in Sherman's formation. McPherson continued to move along the Georgia Railroad toward Atlanta, allowing a small force of Confederate cavalry under Joseph Wheeler to slow his pace. By July 20, he came within striking distance of the Outer Line.