How did photography influence the Civil War?

It is generally accepted that the US Civil War was the first major war covered by photographers.

For the first time, people had photographic images of the death and destruction seen in war.

The Mexican-American War was one of the first extensively covered in moving pictures, and the Vietnam War was one of the first broadcast daily into people's living rooms.

The Gulf War (1991) was amongst the first war to be covered by a 24 hour news channel.