Official History’s Second Day:

The following is the how David Wilson Reed described the second day’s fighting in the first edition of the official history. A few years later a new edition was published by Reed which included the addition of some new paragraphs. It seems that all existing paragraphs were kept the exact same but new items were added. In the case of the second day's actions Reed added six paragraph's from General Beauregard's article in Century Magazine (which eventually became the Battles and Leaders set of books). This version, first edition, is from the Ohio Commission’s dedication book:

The early and determined advance of the Union Army soon convinced General Beauregard that fresh troops had arrived. He, however, made his disposition as rapidly as possible to meet the advance by sending General Hardee to his right, General Bragg to his left, General Polk to left center and General Breckinridge to right center with orders to each to put the Confederate troops into line of battle
without regard to their original organizations. These officers hurried
their staff officers to all parts of the field and soon formed a line for
Hardee, with Chalmers on the right in Stuart’s camps. Next to him was
Colonel Wheeler, in command of Jackson’s old brigade; then Colonel Preston Smith
with remnant of B. R. Johnson’s Brigade; Colonel Maney with Stephen’s Brigade;
then came Stewart, Cleburne, Statham and Martin under Breckinridge; Trabue,
across the main Corinth road just west of Duncan’s, with Anderson and Gibson to
his left under Polk; then Wood, Russell and Pond, under Bragg, finishing the
line to Owl Creek. Very few brigades were intact; the different regiments
were hurried into line from their bivouacs and placed under the command of the
nearest brigade officer, and were then detached and sent from one part of the
field to another as they were needed to reenforce threatened points, until it is
impossible to follow movements or determine just where each regiment was
engaged.

Monday’s battle opened by the advance of General Lew Wallace’s Division on the
Union right, attacking Pond’s Brigade in Hare’s Brigade camp, and was continued
on that flank by a left wheel of Wallace, extending his right until he gained
the Confederate left flank. Nelson’s Division commenced its advance at
daylight and soon developed the Confederate line of battle behind the peach
orchard. He then waited for Crittenden and McCook to get into position and
then commenced the attack upon Hardee in which he was soon joined by all troops
on the field. The fighting seems to have been most stubborn in the center,
where Hazen, Crittenden and McCook were contending with the forces under Polk
and Breckinridge upon the same ground where W. H. L. Wallace and Prentiss fought
on Sunday.

The 20,000 fresh troops in the Union Army made the contest an unequal one, and,
though stubbornly contested for a time, at about 2 o’clock General Beauregard
ordered the withdrawal of his army. To secure the withdrawal he placed
Colonel Looney, of the 38th Tennessee, with his regiment, augmented by
detachments form other regiments, at Shiloh Church, directing him to charge the
Union center. In this charge Colonel Looney passed Sherman’s headquarters
and pressed the Union line back to the Purdy road; at the same time General
Beauregard sent batteries across Shiloh Branch and placed them on the high
ground beyond. With these arrangements Beauregard at 4 o’clock safely
crossed Shiloh Branch with his army and placed his rear guard under Breckinridge
in line upon the ground occupied by his army on Saturday night. The
Confederate Army retired leisurely to Corinth, while the Union Army returned to
the badly demoralized camps that it had occupied before the battle.[1]

[1] Ohio at Shiloh pp 111-2.