Lundgren Family of Iowa

I am looking for information on the family of my gggrandfather, Oscar A. Lundgren b. July 9, 1859 in Småland, Sweden.Oscar was married to Josephine W. Byloff b. April 24, 1856 in Norshirping, Sweden.They had 6 children:Josephine, Oscar Adolph Emanuel b. Dec. 2, 1883 in Sweden, Herman Theodore b. March 16, 1887, George Ruben b. April 30, 1889, Elmer Everett Magnus b. August 16, 1892, and Hazel Josephine b. Sept. 2, 1898.I am a descendant of Elmer Lundgren.