Kennesaw was a routing by Johnston. It's painful to think of the blue wave building up those earthworks and being pushed back each time, but that was the Union strategy.
There were so many routs on both sides in the Civil War. Strategy had not caught up with technological developments. Rifles could now hit accurately at 300 yards, instead of 100 yards, so it was a much more deadly war.
In the Revolutionary War, they complained of a 500-800 being killed. The worst battles of the Civil War were over 10,000 dead, sometimes that many per side.
It was on the hill at Point Park, Nashville that the canons did not work well. The slope down which they aimed was so steep that the canon balls just rolled out before they were lit.
We saw one true canon demonstration at Vicksburg, and several soldiers in attire talking about their life as soldiers. Such events were very effective.