He married Ione Keefer in 1919. She died in 1920 in Elgin, Illinois.
John married Grace Higgie in 1921.
He was a physician in Cicero, Illinois. He was the Medical Officer at the Illinois Institute of Technology. 
He passed away in 1962.
Illinois Rites Held for Famed Native of City
Funeral services for Dr. John C. Smith, 65, of Riverside, Ill, a native of Redwood Falls, were held Monday afternoon in Clement Presbyterian Church in Cicero, Ill, where he had taught a Bible class for 28 years, was a church elder and often served in the pulpit in absence of teh pastor. Interment was in Rosehill Cemetery.
Dr. Smith suffered his first coronary attack on Christmas Day and died of a heart attack at his home Thursday. Hew as born on a farm near Redwood Falls in April 1897 and attended school here. When his sisters went to Missouri to attend Park Collge at Kansas City, he went with them and completed high school and later attended Park college where he was honored at graduation in June this year as its Outstanding Alumnus. At that time he visited in Redwood Falls, his first visit here in 23 years.
↑ "Minnesota Births and Christenings, 1840-1980," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:FD77-BZB : 10 February 2018), John Colville Smith, 29 Mar 1897; citing Paxton Twp., Redwood, Minnesota, reference v B p 18; FHL microfilm 1,321,601.
↑ "United States Census, 1910," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M2G1-VZL : accessed 7 February 2019), John C Smith in household of Andrew D Smith, Paxton, Redwood, Minnesota, United States; citing enumeration district (ED) ED 121, sheet 2B, family 26, NARA microfilm publication T624 (Washington D.C.: National Archives and Records Administration, 1982), roll 713; FHL microfilm 1,374,726.
↑ "United States Census, 1930," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:XS5Y-KDJ : accessed 7 February 2019), John Smith in household of Alice Higgie, Cicero, Cook, Illinois, United States; citing enumeration district (ED) ED 2080, sheet 20A, line 33, family 362, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 498; FHL microfilm 2,340,233.
↑ "Minnesota, Obituaries 1865-2006," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:Q2WL-SX7L : accessed 7 February 2019), Dr John C Smith, 1962; citing Redwood Falls, Redwood, Minnesota, United States, newspaper Redwood Falls Gazette Southwest Minnesota Historical Center, Marshall. ; FHL microfilm 7,618,895.
Find A Grave: Memorial #196662717 Find A Grave, database and images (https://www.findagrave.com : accessed 06 February 2019), memorial page for Dr John Colville Smith (29 Mar 1897–2 Aug 1962), Find A Grave Memorial no. 196662717, citing Rosehill Cemetery and Mausoleum, Chicago, Cook County, Illinois, USA ; Maintained by Joelle Colville-hanson (contributor 48735492) .