[if you can add anything to this family data, please contact Steven and/or Roberta]
There is no death record for Uncle Columbus Delano Severns---not unusual in Iowa in that time period. I couldn't even find an obituary in the Bedford Free Press---the local weekly newspaper. I checked the issues for 18 Jul 1901 and several weeks thereafter. He is not mentioned in the old county histories; I did find his name on an 1890 tax list. I found him and his wife on a cemetery list:
Ladoga cemetery, in Section 30 of Washington township, Taylor county, IA, row 7:
Columbus D. Severns died 18 Jul 1901, aged 69y 3m 14d; Co I, 28 Illinois Infantry
(that's Company "eye", no L)
Hannah A., his wife 1833-1911
I was hoping his sister Harriet might be buried with them, but no such luck.
However, I did find her death record! Deaths in Taylor county, IA, vol. 3, p. 79, #41:
Severns, Herriott, age 83, born 1830 in Ohio; single; died 2 Oct 1913 at the Taylor County Home in Marshal township; died of old age and anaemia; how long a resident of the home: 12 years; buried County Home on 3 Oct 3; names of parents unknown; informant William R. Rice, Conway, IA.
Elsewhere I learned the Taylor County Farm cemetery is in the southern part of Section 29 in Marshall township. No legible stones anymore.
In 1909 the Taylor County Poorhouse was renamed the Taylor County Home.
Two entries below Harriet's in the death records is a very sad one: a 9-month-old girl died of "drowning in slop bucket."
There are many Severns in the Taylor county histories; but they are not Uncle Columbus nor his children. I think I finally sorted them out: James Riley Severns, last of seven children born to Ezekiel and Ruthette (Pettit) Severns. James Riley Severns born 11 Feb 1844 while they still lived in Coshocton county, Ohio, and was only five years old when his father died in 1849, and age eleven when the family moved from Illinois to Iowa, finally settling in Taylor county, Iowa in 1859. James Riley Severns married Florence Ann Burrell and had 9 children: Ulysses, Amanda (Mrs. William J. Sloan), Benjamin, Albert, Eustace, William, Walter, Charles, and Clyde.
According to cousin Maggie Severns (Mrs. Francis "Red" Severns), her husband's great-grandfather, Columbus Delano Severns, was born in Coshocton county, Ohio, when the Nye Severns family lived there. Columbus Delano was an Ohio politician the same time our Nye lived there; so I suspect Nye named his baby son after a man he admired, and likely knew.
So it looks to me like Uncle Columbus settled in Taylor county in southwestern Iowa where he already had Severns cousins. Uncle Columbus' son Blair---named after Columbus' younger brother Blair; it gets confusing!---was Red's grandfather, born in 1869.