Perhaps what I have will help you. Don't know if they are the same people. (email@example.com
Edward Morgan is said to have been born somewhere in Australia, possibly around 1836.
At some point, possibly with his family, Edward migrated to the United States, settled down in the State of Pennsylvania and upon the outbreak of the American Civil War enlisted as a substitute for another soldier, as a Private into Pennsylvania Volunteers, Company “F” 81st Pennsylvania Infantry; likely after being paid a sum of money for doing so, as that was quite common at the time. Many after doing so never reported for duty, and some enlisted as a substitute for different soldiers repeatedly to acquire more money.
In the Pennsylvania and National Archives archives military records on Pennsylvania soldiers, Morgan was found to have been recorded under three different spellings of his name. He was recorded as Edward Morgan; Edward Mangain and as Edward Magain. All three were recorded as aliases of the same man serving in Company “F” 81st Pennsylvania Infantry. The name ‘Morgan’ has also been used and spelt as “Mangan and Mangon” from year to year and continent to continent; according to one of the descendants.
The 81st Pennsylvania Infantry was organized at Philadelphia, Pennsylvania the first week in October 1861. It remained at Easton, Pa. until October 10th when it moved to Washington, D. C. in the defense of Washington D. C., remaining there util March, 1862 when it advanced on Manassas, Virginia. On October 10th it was attached to Howard's Brigade, Richardson's Division, Army Potomac until March, 1862 and then to the 1st Brigade, 1st Division, 2nd Army Corps, Army Potomac until June, 1865.
The 81st Pennsylvania Infantry was an active regiment, seeing many battles and conflicts; but it is believed Edward Morgan never participated in any of them; as he was said to never have joined his regiment after enlisting as a substitute. As such, there is no record of his having ever received a discharge; the only record being his initial Muster Roll Index Cards, which contain nothing.
I also found the attached; maybe they can help you.