Joseph K. F. Mansfield, Brigadier General of the U.S. Army by John Mead Gould

The next question that arises is, why did Gen. Mansfield suppose the 10th Maine was firing into Union troops?

While the corps was waiting in the vicinity of Joe Poffenberger's, (marked 6:20 on the map) from about 6:20 to 7:20 A. M., Gen. Mansfield was seen frequently by almost every soldier of the corps. In hundreds of letters, from the various regiments and batteries, there is a common agreement that the General was moving around the field continually. He seemed to be everywhere. Although he appeared like a calm and dignified old gentleman when he took command of the corps two days before, on this fatal morning he was the personification of vigor, dash and enthusiasm. As before stated, he remained some minutes at the northwest corner of East Woods (W on the map), observing the battle. One gets a fine view of the field from there and he must have got a good insight into the way Hooker's corps was fighting. Presumably the tide was turning against Hooker, and as likely Mansfield had been called upon by him for reinforcements, but when Mansfield left the northwest corner to set his corps in motion, the East Woods, if I have rightly interpreted the reports and correspondence, was still in possession of Union troops. Probably, almost at the same time that Mansfield quitted his lookout, the Confederate brigade of Law (Hood's division) came charging out of West Woods, the 4th Alabama on the right running up the Smoketown road, as before stated, and entering the woods at the south-west corner where the Georgia battalion joined on its right. The movements of all of Hood's troops were exceedingly rapid.