In the 1890 census Schedule of Union Veterans, Henry Geminden of Linn Township, Moniteau County listed service as a Pvt in Co. C, 45th Mo Infantry from Aug 1864 to 3 Jul 1865 and this appears to be him:

http://www.sos.mo.gov/TIF2PDFConsumer/DispPDF.aspx?fTiff=/archives/AdjutantGeneral/Civil_War/ServiceCards/s866/0768.tif&Fln=S124710.pdf

There is also this card listing the unit as 50th Infantry:

http://www.sos.mo.gov/TIF2PDFConsumer/DispPDF.aspx?fTiff=/archives/AdjutantGeneral/Civil_War/ServiceCards/s868/1191.tif&Fln=S124086.pdf