The marker for the Second Brigade of the Cavalry Division is on the south side of Boonsboro Pike east of Rodman Avenue. (Boonsboro Pike tour map)

From the marker:

U.S.A.

Second Brigade, Cavalry Division

Col. John F. Farnsworth, 8th Illinois Cavalry,
Commanding.

Organization.
8th Illinois, 3d Indiana, 1st Massachusetts, and
8th Pennsylvania Cavalry

(September 17, 1862.)

The Second Brigade crossed the Middle Bridge under a severe fire of the Confederate Artillery posted on Cemetery Hill. The 8th Pennsylvania was thrown to the right to support the Artillery north of this road. The remaining Regiments took position in the ravine on the left between this point and the Antietam, where, in support to the Batteries in front, they remained until relieved by the advance of the Regular Infantry, when the entire Brigade was withdrawn. The 8th Illinois and 3d Indiana moved up the west bank of the creek and bivouacked in rear of the right wing of the Infantry line. The 8th Pennsylvania crossed the Middle Bridge, ascended the east bank of the Antietam, recrossed the stream near Neikirk’s and bivouacked near the Illinois and Indiana Regiments. The 1st Massachusetts recrossed the Antietam by the Middle Bridge and bivouacked near Keedysville.

No. 90.