Otto Mann, son of Ludwig Mann, was born in Germany about 1860. He married Mary Schmidt (aka Mary Smith) Oct 1, 1890 in Macomb County, Michigan. They had the following children:

Louis Charles Mann (b 1892)
William August Mann (b 1894)
Elsie Mann (b 1896)
Otto George Mann (b 1899)
Mary Mann (b 1902)

The family appears on the 1900 Census living Macomb County, Michigan. There is a Public Member tree on Ancestry with all of this information.