The three factors which made Gandhi to lead India towards independence were,
1. He saw the dissimilarity among the people, when he was thrown out of the train. So, he thought to overthrow this.
2. His non-violence path lead him to lead India towards independence.
3. His satyagraha, and non-cooperation movement laid basis for India to get freedom.
Jallianwala bagh was a great massacre which was held in 13 April 1919. This massacre was done by General Dyer, who was the general at that time. He ogave the firig order, and thus, killed many people. This was seems to be a turning point of Indian national movement, as after this, the people took the violence in their hands, then, Mahatma Gandhi made to be follow non-violence again. Though, some leaders started to fight through violence.
So, this seems to be a turning point in the Indian history.
Hope this will help you.