Mann & Stern was an architectural partnership in Arkansas of Eugene John Stern and George R. Mann (1856—1939).
A number of their works are listed on the National Register of Historic Places.
Works include (with attribution):
Howard Seymour Stern (1910–2002), son of Eugene, also trained as an architect.
https://www.cardcow.com/213066/albert-pike-consistory-little-rock-arkansas/