Hi, my great-grandpa (John Harrison) served in the war in the Mississippi 11th Cav., Company B from Jan. 1863 to the end of the war...(according to his pension papers). Can anyone give me any information about his company or regiment? Where did they go? What action did they see, etc...

Sometime in the 1920's, he went to a reunion in Arkansas. I have a picture of him with 17 other men, standing in front of a building. They have a Confederate flag with them. It appears to have stars in a circle. I can not see the entire flag because it is not stretched out.
Does anyone know about this reunion?

Thank you!