According to the Adjutant General's (KY) Report, John Easton served as a Private in Captain Thomas Todd's Company I from 1 Oct 1847 until his medical discharge at Vera Cruz, Mexico on 3 Mar 1848. I'm guessing he died New Orleans Louisiana on his way home.
There are two records you can order from the National Archives (
www.nara.gov). His compiled military service record, $25, which probably has his age and maybe a little more information. More importantly, his Military Bounty Land Warrant Application File, $25...his father would have to prove he was the heir and may have other information about the soldier's condition and place of burial.
Hope you share what information you find. The Descendants of Mexican War Veterans (
www.dmwv.org) would like to know where your ancestor is buried and if there is a gravestone.