I found the following entry in Ancestry.com's Headstones Provided for Deceased Union Civil War Veterans, 1879-1903 that might be of interest:

Lowdon, Thomas Pvt. Co. A 18th Reg. Ind Infantry
Cemetery River View Aurora Ind
No date of death given

Headstone supplied by Gross Brothers
Lee, Mass.,
Contracted dated [unreadable] 1891

Tony