I also have an Aden ancestor with the same date of birth and death as your Henrich Menne Aden.The difference I have is mine is spelled Hinrich Mennen Aden.
My Henry was born, 28 Dec 1841 in Hannover, Germany.He died, 21 Mar 1885, Adams County, Illinois, USA.He was married at one time to a woman by the name of "Mary" who's date of birth matches yours.
In the 1870 US Census, I have found they had two children. Mennen, b. abt. 1865 Mary, b. abt. 1869
I then lose "Mary" and find Henry married to a "Maggie" in the 1880 US Census with three children from a previous marriage of Henry. Mennen Mary Frank, b. abt. 1871 - They had 4 children together, which I am finding information on. Weubke (Carrie) b. abt. 1879 Alta (Etha/Ella) b. abt. 1881 Fredrick Henry b. abt. 1883 (my ggrandfather) Ehme b. abt. 1884
Henry and "Maggie" died rather suddenly in their young age, and the last four children were raised by "Maggie"'s brother Hiram Berhends.
Could we have a common connection?Could have your Ettje Maria Leenerts have gone by the name of "Mary"?