In the responces to my question a few senders refered to the website http://www.minonktalk.com/genealog/gbarth/Ruestman/TheFRustmanFamily.html , where it says that Johann Peter RÜSTMANN took some cows to market on April 1, 1879.
According to the newspaper "Ostfriesische Nachrichten", of November 10, 1927, published in Breda, IA, it mentioned the year of 1877 for the death of Anna RÜSTMANN's husband. Two years later she came with her children to Minonk, Illinois.
In the website http://www.online-ofb.de/famreport.php?ofb=stedesdorf&ID=21895 it gives the burial date with April 1, 1879 in West Dunum.
Was he buried on the same day he went to the market, got robbed and murdered and was found in the North Sea ?