The family arrived in New Orleans in Dec 1846 from Speyer Germany. BY 1860 they were in Indianola Texas. FHH had 3 brothers, Jacob who was in the 8th Tex Inf; F A Hamm who joined the 1st Special La Inf (Wheat's); Lewis who joined the 30th Tex but left and went up north and joined the 18th Indiana Inf. How they all split up is not completely know but I do know the Germans in south texas wanted nothing to do with the war or slavery. Lewis and Jacob did write a few times after the war, but never saw each other. Lewis died in 1920 in a VA home in Indiana, Jacob died in 1893 in Cuero Texas. F A ended up in Tx and La and got a pension from La. He died in 1901 in New Orleans.
As far as F H H goes, nothing is know after the war. My aunt who died in 1973 always told how the Civil War caused the 4 brothers to split and one to go to the Union side. I believe their sister returned to Germany before the war began. Their father Johann died before 1870 and the mother some time after. Their burials were destroyed by the 2 bad hurricanes when Indianola TX was destroyed.
F H H was listed as a bucher, F A was a flag carrier and was wounded at the 1st Bull Run, Lewis was a baker and cook, and Jacob was a boot maker so as far as actual combat
is unknown. I have a distant cuz from Lewis in Flordia that was told that Lewis and Jacob was only a corn field apart at some battle but I have never confermed this.
Sorry for the rambling, I am sure many civil war familys had stories as such.
As for F H H, it is possible his brothers may have never know what happened to him. He is in the 1860 cenus as F H Ham(H), as a barkeeper living in the Phenix House owned by Catherine Elsaser, who he married in 1860. I confermed this on my last vist to Vicksburg this year.

James Hamm