Issued General Orders No. 22, “In pursuance of Special Orders No 78 from Head Quarters, Department of the Missouri, the name of this Military District will be known as the “District of Cairo”, and will include all the Southern part of Illinois, that part of Kentucky west of the Cumberland River, and the southern counties of Missouri south of Cape Girardeau.
“All troops that are or may be stationed along the bank of the Ohio, on both sides of the River, east of Caledonia and to the mouth of the Cumberland, will be included in the command having Head Quarters at Paducah, Ky.”
The Papers of Ulysses S Grant, Vol 3 p 331
National Archives, RG 393, USG General Orders