Family of James Corcoran

I am searching for information on the family and history of my great grandfather. His name was James W CORCORAN born in Pennsylvania in 1877. He married June OLIVER on 10 Nov 1899, in Logan, Iowa. I have no further information on June OLIVER or their marriage. Not sure if the marriage was anulled, they divorced or if June died. On 25 Oct 1905 James W CORCORAN married Sophie Auguste Louise ZELL (31 Dec 1886-23 Jun 1961) in Bremer County? Iowa. They had 2 children, William Carl Corcoran (Volker) 17 Feb 1906-4 aug 1994, and James August Corcoran (Volker) 13 Oct 1908- 27 Nov 2005.The children were later adopted by Sophie's second husband Frederick W VOLKER. On the marriage license James' parents are listed as James CORCORAN and Clarrisa Belle Cornish. I have been able to trace Clarissa's line but have been unable to find anything out about my Corcoran heritage. James W CORCORAN died in Omaha,Nebraska on 15 Sep 1914 from possible suicide. I have a few pdf files about his death from the Omaha papers at the time but none of those help in tracing his family. Any help would be greatly appreciated.