Battle of Stones River

"it was an important victory for the Union because it provided a much-needed boost in morale after the Union's recent defeat at Fredericksburg[1][2] and also reinforced President Abraham Lincoln's foundation for issuing the Emancipation Proclamation,[1] which ultimately discouraged European powers from intervening on the Confederacy's behalf." - https://en.wikipedia.org/wiki/Battle_of_Stones_River