I know that Johnson's 14th Texas Calvary ( The last commanding officer that I am aware of was Capt. Stephen C. Regan) was in the 2 hr fight that took place on 7th Apr 1964 which was the day before the battle of Mansfield and Pleasant Hill. My gg grandfather, John Wesley Conner (Newton County, Texas) was killed during that fight. I have been researching this for a long time. Maybe other's will have more information that I do.