Looking for Post 1870 Information for James S Marshall Born C 1820

I have not been able to find any information for James S Marshall (born c. 1820 in Ohio or Virginia) after the 1870 US Federal Census. James married Rebecca Ann Bond in 1851 in Ohio and arrived in Louisa County between 1852-1856. They had one son, Alonzo L Marshall. James and Rebecca lived in Marshall Township in 1870. I cannot find anything more about either of them after that and am very interested in knowing when and where they died. Any help would be appreciated.