Answer:
suffered losses so heavy that he could no longer mount an effective defense
Explanation:
Battle of Gettysburg is part of the many battles between the Confederates (Army of Northern Virginia) and the Union (Army of Potomac) during the American Civil War, which occurred between July 1 - 3 in 1863. In this battle, General Robert E. Lee suffered losses so heavy ( with total casualties estimated to be in the region of 23,000 - 28,000) that he could no longer mount an effective defense. He later asked to be replaced by the Confederates president Jefferson Davis.
The animal that changed their ways was the horse.
I will say it's C. It extended over three major continents.
It is hanled by gaurds or patrols
