My grandmother Fern Busby Parsons, wife of Cyril Parsons (son of Clarence and Sophia Parsons) did some genealogy research while she was alive - before the age of computers. I'm attaching a copy of portion of the chart she had started. It shows a marriage date for Alexander and Adda as June 6,1864, however I do not have a record to back this up. My father has 2 boxes with Fern's records. I recently visited my father and we were going through the boxes and found a picture of a civil war soldier I believe to be Alexander Parsons which led me to this thread and gave me the answer to what I was looking for - the regiment he served under. Fern had quite a bit of correspondence with relatives and the wedding date may be in there somewhere. Just not sure.
You may already know this but I show Parsons as originally a French name of "Paissant" or "Poissant" from St. Edmonds, Quebec. Also show Adda's mother Flora King's maiden name as "Rougeau"
Jo Ellen Parsons Leger