Although there were at least five photographers east of the Mississippi named Mendenhall in the cabinet card era, only one was in the area of Marysville, MO, David D. Mendenhall. D D Mendenhall also had a photographer son who should accounts for the Mendenhall and Son imprints.
David D Mendenhall
Frank M Mendenhall
Ohio, David D Mendenhall born
1857 Nov 04
Fulton county, IL, city register, David D Mendenhall marries Sarah Antoinette Moore (1840-1908)
1858 Aug 06
Farmington, IL, city register, Frank M Mendenhall born
1860 Jul 20
US census Farmington, IL, David D (as painter), wife Antoinette and son Frank
1870 Aug 03
US census Farmington, IL, David D (as photographer), wife Amanda and son Frank
1880 Jun 11
US census, Elmwood, IL, David D (as photographer), wife Amanda; Frank has moved away
1900 Jun 09
US census, Maryville, MO, David D as photographer at 608 n Main; as widowed
1905 Feb 29
Maryville, MO, David D Mendenhall dies at age 69
Sarah Antoinette Moore Mendenhall dies at age 68
Illinois, Frank M Mendenhall dies at age 93
It is apparent that David D Mendenhall moved to Maryville, MO, sometime after the 1800 census. He operated there until his death in 1905.
When his son Frank lived in Maryville, MO, is not documented but it must have been for only a short time as all other documents place Frank in Canton, IL, from 1884 until his death in 1951.
In city directory listings of Frank Mendenhall, he is never in the business sections as running his own studio. He apparently worked for other photographers. This would make him free to move for short periods to Maryville, MO, to work with his father, David.
The cabinet cards above would have been done between about 1900 and 1905.