Lew Wallace's Division missed the first day of combat. They were stationed north of the battlefield to protect against a possible move against Crump's Landing. Ever since then Wallace has been the subject of much debate, centering on how long it took his division to reach the battlefield. In a future post I'll go through all the various evidence for and against him, right now I want to continue in my series of posts covering the order of battle.
The brief version is that when the sound of battle was first heard, Wallace boarded a steamer at Crump's Landing so that he could talk with Grant as he passed from Savannah to Pittsburg Landing. In this very brief exchange Grant said to get ready and orders would come as soon as he knew the situation. Quickly after Grant arrived on the battlefield it was obvious that this was the main Confederate effort and Wallace could leave his camps. Sometime around noon Wallace leaves his camps and heads to the battlefield on one road, later Grant's staff over takes him and says his road is in enemy hands and he should take a different road. Wallace turns around and winds up on the battlefield as the battle closes on April 6th.
On April 7th he'll form the right flank of the army and move (generally) from the Jones Field area to an area just west of Woolf Field. Some also think his actions on day two were also subpar.
Third Division - Major General Lewis Wallace (OR report)
First Brigade - Colonel Morgan L. Smith
11th Indiana (OR report)
24th Indiana (OR report)
Second Brigade - Colonel John M. Thayer (OR report)
1st Nebraska (OR report)
23d Indiana (OR report)
58th Ohio (OR report)
Third Brigade - Colonel Charles Whittlesey (OR report)
20th Ohio (OR report)
Since Wallace's camps are outside of the park boundary there are no monuments for his headquarters or camps. In Adamsville is this marker put up by the Tennessee Historical Commission.