On looking into S. Grillette (Footnote.com), I found a military record of 17 pages. He was listed severally as S., Spir and Spear, and also Grillett, Grilette and Greleitt. He enlisted in Co D of the Third Louisiana Infantry, was detailed as regimental teamster for a while, was wounded on June 10, 1862 in the trenches at Vicksburg, was surrendered on July 4, 1863, and was paroled at Vicksburg on July 14, 1863. Although I did not try a variety of spellings, I did not find Grillette or Grillet in the 1860 US census.

Don Parker