The Battle of Arroyo Grande took place on 6 December 1842 and was a major battle of the Uruguayan Civil War.
Battle.
At Arroyo Grande, the federal forces, or "blancos", of Manuel Oribe defeated the "colorados" of Fructuoso Rivera, having been in conflict with them since 1838.
Aftermath.
Following the battle, Oribe followed up his victory over the Colorados by marching to and besieging Montevideo thus beginning the Great Siege of Montevideo.