Here’s one report found in the ORs.
Try a Goggle Search
Olney
at:
http://ehistory.osu.edu/books/official-records
OLNEY, ILL., July 22, 1863.
Colonel OAKES,
Acting Assistant Provost-Marshal-General for Illinois:
A body of 200 to 500 men came within half a mile of our town last night to destroy enrollments. The papers were all secured and the raid stopped for a time. Rumors came in frequently of further danger. Captain O"Kean gone to Franklin. We send messenger by train to-day.
H. STUDER,
Assistant Provost-Marshal.
OR Series III, Vol.III, p. 560