There is a Kentucky death record for John Huston on 31 Mar 1873 in Louisville, KY. If Lucy remarried because John died, this is a possibility.
John married Lucy in Havana, IL which is in Mason County so possibly there are other Hustons in this location that could lead to something new.
On the marriage record for John and Lucy, it says that he is John D. Huston. There is a Civil War pension record for a John D. Huston in Illinois - maybe a lead to pursue. If not, maybe look at other Civil War pension records since he could have served in the Civil War.
John D. Huston, "United States, Civil War and Later Pension Index, 1861-1917"
Name: John D. Huston
Military Rank: P.
Military Company: I
Military Regiment: 60
Military Unit: Infantry
Event Date: 13 May 1882
Affiliate Name: National Archives and Records Administration
Affiliate Publication Number: T289
Affiliate Publication Title: Organization Index to Pension Files of Veterans Who Served Between 1861 and 1900
Affiliate Record Type: Civil War Pensions
There is a family tree on ancestry named Jasper-Tucker-Rule-Campbell Tree that might be a match with your John Huston.