Indeed it was a historic and decisive day for India on 15 August 1947, on this day, India got independence from British rule after 100 years. However, the background of this decision was prepared on 3 June 1947.
This decision was the result of an agreement between the Congress and the Muslim League in presence of Lord Mountbatten. While on one hand it brought rain of happiness, on the other hand it was also accompanied by storms of sorrow. Gandhi Ji was also an important figure covering this sadness because though the decision taken on 3 June 1947 was pleasant but there was one aspect to it which was the partition of India, i.e. the creation of a separate state called Pakistan from India, which was formed based on religious beliefs.
As it is well known that Gandhi ji used to emphasized and support non-violence and unity from the starting but this division not only attacked unity but also inflicted violence on non-violence, as after this decision, communal riots occurred in major part of India like Bengal, Bihar etc and several people died.
The Congress was not in favor of this decision and it was also strongly opposed by Gandhi ji. To communicate and convinced Muslim League and other leaders Gandhi took long hikes and did fast to advocate and spread non-violence propaganda but due to inferiority of Mohammad Ali Jinnah and the majority communal vision, the partition of India finally got acceptance.
On 15 August 1947, Gandhi ji did not attend Delhi but was immersed in grief in Kolkata.
He fasted on this day and addressed the large population to pave the way for unity and non-violence. It was already made clear by Gandhiji that future generations must understand that he did not contribute or support partition of India based on religion in any way. He always invoke the path of non-violence, pre-scripture and truth.
Gandhiji was a global legend, Which we can assess from the fact that at his death the international body United Nations had also tilted its symbol flag down. Gandhi observed Aug 15th 1947 as a sad day and did not participate in any celebration.