Gregg had two brigades present at Gettysburg, under Col. John B. McIntosh and Col. J. Irvin Gregg (David Gregg's cousin), but the latter was stationed on the Baltimore Pike.
Gregg havde to brigader tilstede ved Gettysburg, dem under oberst John B. McIntosh og oberst J. Irvin Gregg (David Greggs fætter), men den sidste var placeret på Baltimore Pike.