Peter Hans Marxen, b. 22 Sep 1830, Flensburg, Schleswig-Holstein, Denmark/Germany, married Anna Monicous 1862 in Flensburg. To the best of my knowledge they had four children: John C. Marxen, b. 01 June 1863; Dorothea, b. unk; Charlotte, b. unk; and Nicholas, b. unk.
John Marxen came to the U.S. in the 1880s. He spent some time in Davenport, Iowa and then moved on to Omaha Nebraska where he married Amalie Rethwisch. John Marxen died 3 Mar 1943 in Omaha.