History of North America

What was Robert E. biggest mistake in the civil war?

Failing to seize the initiative after his victories at Second Manassas and Chancellorsville:

- Following his victory at Second Manassas in August 1862, Lee chose to pursue the defeated Union army rather than move on Washington, D.C., which was relatively undefended at the time.

- Again, after his success at Chancellorsville in May 1863, Lee hesitated to exploit his victory fully, allowing the Union Army to regroup and dig in along the heights of Cemetery Ridge at Gettysburg, leading to his decisive defeat there.