...sisted the other students in getting their lessons, doing sums for them and helping in various ways. O'Hara became a captain in the Second Regiment of Cavalry in 1855, and while on the march from Jefferson Barracks, Missouri , to Texas, in the fall and winter of 1855-56, was attentive to his company. One evening after the regiment had halted for the night, where there was some tall, dry grass, a fire broke out, and it r...