I may have some information for you on William FELKER. This is not my direct line, but my great-grandmother's sister, Nancy Ellen TAYLOR married Sherman FELKER. One of their children was William born 14 Feb 1885. He was born in Missouri, probably either Stoddard or Dunklin counties. According to the Social Security Death Index, he died in Mississippi in March 1966. I have not done much research on the FELKER line, but I did find the 1880 census with Sherman and his parents and siblings in Dunklin County, MO and I have the 1900 census with Sherman's new family in Stoddard County, MO. I have also looked up the children on the SSDI and have found several listed. Since FELKER is not a common name, there isn't much problem finding the ones you're looking for--if they are listed.
I hope this helps. If you need more information, please let me know.