What was the major battle in the US Civil War?

Answer 1

There were quite a number of major battles, depending entirely on your perspective and what you consider major. Generally, Gettysburg is considered one of the turning points as it was the last offensive by the south. The siege of Vicksburg is another, as it cut the south off from their western regions and gave the Union complete control of the Mississippi River.

Answer 2

Many of the most historic battles of the war took place in the midpoint year of 1863.

The most legendary was Gettysburg, often called the Confederate High Watermark - a dramatic moment in American history, when Lee was defeated by the Union army under George Meade, only days after the latter's promotion to army commander.

It marked the end of Lee's hopes of invading Pennsylvania and the North. But the battle cannot really be considered in isolation from the other one that ended on the same day - Vicksburg, the last Confederate stronghold on the Mississippi, captured by Grant after a major siege. This was immensely significant, as it ended the war in the West, and cut-off all Confederate troops on the far side of the river.

Lee's campaign was partly aimed at making Lincoln nervous about the safety of Washington, and summoning part of Grant's army East to counter the threat.