The Todd’s Tavern – March to Spotsylvania wayside marker is at a pull-off on Brock Road at Todd’s Tavern, about 12 miles southwest of Fredericksburg, Virginia and halfway between the Wilderness and Spotsylvania battlefields. (38°14’51.8″N 77°40’07.4″W; map) 
Todd’s Tavern
March to Spotsylvania
Lee vs. Grant – The 1864 Campaign
After two days of inconclusive fighting in the Wilderness, Union Gen. U.S. Grant determined to push on to Spotsylvania Court House, ten miles south. Possession of the roads near Spotsylvania would give the Army of the Potomac the inside track, forcing Lee either to attack or race to Richmond using a longer route. Just as important, marching to Spotsylvania would get the Union army out of the Wilderness and into more open ground, where it could take advantage of its superior numbers.
Grant’s men began their march to Spotsylvania after dark, May 7, 1864, The Fifth and Second Corps took the Brock Road (the same route you have been traveling); the Sixth and Ninth Corps followed roads further to the east. Unknown to Grant, Lee’s army was headed to Spotsylvania, too. The outcome of the campaign would hinge on who reached the town first.
From the caption to the inset photo:
Richard H. Anderson led the Confederate march to Spotsylvania
From the text in the inset box:
Headquarters Armies of the United States
May 7, 1864 6:30 a.m.
Major General Meade
Commanding Army of the Potomac
General: Make all preparations during the day for a night march to take position at Spotsylvania Court House.
U.S. Grant
Lieutenant General