He was still married to Caroline in Connecticut in 1880.
Nancy died a Rhodes in 1900 (specific date not given):
"Connecticut Deaths and Burials, 1772-1934", database, FamilySearch (https://familysearch.org/ark:/61903/1:1:QLMW-WP2V : 29 November 2018), Nancy D Rhodes, Wethersfield, Hartford, 1900. Father George Rhodes.
Here's Caroline and Nancy with their family in 1860:
"United States Census, 1860", database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MHR8-615 : 18 March 2020), Nancy D Rhodes in entry for George Rhodes, Wethersfield, Hartford, Connecticut, 1860.