The Indiana Genealogical Society has published an index to the 1890 soldiers enrollment list for Marshall County. It is available for purchase in the Shop on the IGS website.
The soldiers enrollment lists enumerated the veterans of all past wars (including the Civil War) who were living in that county in 1890. If the veteran was deceased, the list included information on their widows and children. The Indiana Genealogical Society's indexes contain detailed information from these lists and are on CD-ROM. IGS has now published the indexes for 85 counties.