...omac and Antietam, their flanks and rear protected by these streams, was one of the strongest to be found in this region of country, which is well adapted to defensive warfare. On the right, near Keedysville , on both sides of the Sharpsburg turnpike, were Sumner's and Hooker's corps. In advance, on the right of the turnpike and near the Antietam river, Gen. Richardson's division of Gen. Sumner's corps ...