Hey CDHolmes,
You might want to look at the Descendants of Mexican war veterans website. It has a list of all the officers and men who were wounded or killed in the war from the lst Mississippi rifles. My ancestor Edward Ulysses Cohea was at Buena Vista. He was not wounded or killed and went to San Francisco after the war. He was a policeman there and when he died in 1869 was given a policeman's burial.
Dana