BATTLE OF SPOTTSYLVANIA—HANCOCK'S POSITION—ASSAULT OF WARREN'S AND WRIGHT'S CORPS—UPTON PROMOTED ON THE FIELD—GOOD NEWS FROM BUTLER AND SHERIDAN. The Mattapony River is formed by the junction of the Mat, the Ta, the Po and the Ny rivers, the last being the northernmost of the four. It takes its rise about a mile south and a little east of the Wilderness Tavern. The Po rises... more...