While at Harvard, Henry L. Abbott became very good friends with fellow classmate Lane Brandon of Wilkinson County, Mississippi. When the war came Brandon joined the 21st Mississippi Infantry, and as fate would have it, his regiment ended up facing the 20th Massachusetts on numerous battlefields. In 1866, Brandon wrote a letter to Henry Abbott's father and told him, "It is remarkable that our brigades should have met face to face on so many fields. In fact, Henry's old brigade became so well known to us, that several times when the fighting would become warm and stubborn I have heard the remark, 'boys these must be the old fellows - they fight mighty like it.' My company was stationed all winter '61 until March '62 on picket at Ball's Bluff. Three regts. of my brigade participated in the engagement at this place on [21st] Oct. 1861, but my regt. was not assigned to the command until some time subsequent. We renewed our acquaintance on the evening of 31st May at Fair Oaks or Seven Pines - the meeting was a warm one for us. We next met on [the] evening of 30th June at Glendale, mentioned in Genl. Lee's report as Frazier's Farm, & again on Tuesday evening 1st July at Malvern Hill. Then in the streets of Fredericksburg night of Dec. 11th, '62 & Marye's Heights May 3, '63...Before closing I will add that none of my immediate family were killed in the war - And that if you can write 'Charity requires us to suppose there were a great many honest persons on both sides, and duty requires us to do justice to all,' how much more ought that sentiment to be binding on me, and I trust I will not prove recusant to it."