After the publication of the Declaration of Independence, all India–and much of Britain, too–waited anxiously to see what Gandhi would do next. By February of 1930, his mind had turned to salt. Under the Salt Laws, the British government had a monopoly on salt, controlling both its production and distribution. It was against these laws that Gandhi now turned the force of satyagraha.

On March 2, 1930, he sent a famous letter to the Viceroy Lord Irwin, warning him that beginning on March 11 he and the other members of his ashram would begin breaking the Salt Laws. Irwin–who would later take the title Lord Halifax–was a deeply religious person, with a great respect for Gandhi, whom he called "the little man," and agonized before deciding not to arrest the Mahatma before seeing what course his disobedience would take. He did not have long to wait. On March 12, having given the Viceroy an extra day, Gandhi and seventy-eight others left his ashram and began to walk the two hundred miles to the seacoast. There, he declared, he would take a pinch of salt from the Indian Ocean, thus violating the laws of the Empire, which declared that only the British could harvest salt.

Practically, of course, the Salt March was a meaningless gesture. But as an act of political theater, it had astonishing power. The attention of the world was now focused on western India, where the "little man," accompanied by crowds from every village he passed, spent twenty-four days walking to the sea. He reached it on April 6, and took salt from the ocean; soon, all over India, the subjects of the Raj followed suit, disobeying the Salt Laws in massive numbers: the Congress organized the sale of illegal salt on a huge scale, and mass meetings took place in every major city. The British government cracked down–throwing people in jail, censoring the press–but all to no avail. Soon the prisons were full to bursting with Indians, all of whom followed Gandhi's lead and made no resistance. It was satyagraha on an unprecedented scale, and the Viceroy was helpless against it. In desperation, he ordered the Indian leaders arrested, beginning with Jawaharlal Nehru and ending, on May 5, with Gandhi. But still the demonstrations went on, lasting nearly a year, and finally, in January of 1931, the government yielded. The prisoners were released and Gandhi met with Lord Irwin, who agreed that the Indian National Congress could send a representative to the Round Table Conference, to be held in London that fall. There was no question as to who the Congress' representative would be.

This was the peak of Gandhi's career. Despite the groans of men like Winston Churchill, who saw in this "half-naked fakir" the downfall of Britain's Empire, he received a friendly, even adulatory greeting from the British when he arrived for the Conference that fall. Leading Englishmen, from the King to George Bernard Shaw, lined up for interviews, and large crowds followed him wherever he went. In a sense, it was this "public relations" side of the Round Table Conference that achieved the most for India, as Gandhi built considerable support for independence among the British public. The Conference itself, unfortunately, was an utter disaster–no plan for independence or home rule could be agreed upon, because of British concern over the treatment of minorities (especially Muslims) in a Hindu-dominated India. This difficulty was not a new one: the Muslim League, founded by Muhammed Ali Jinnah, had become a significant force in Indian politics, and its demands would make the road to independence a rocky one.

When Gandhi returned to India in late December of 1931, the British were cracking down again after a Congress campaign against British landlords. Nehru had already been arrested, and so too was Gandhi, only a week after his return home. He was given no trial, nor were any charges brought–rather, he was held at the discretion of the British government. While he was prison, the British set out to create separate electoral systems of Hindus, Muslims, and untouchables, to ensure that each would have representation in provincial legislatures. To Gandhi, the idea of dividing Indians by religion was objectionable, and the idea of dividing them by caste was intolerable. He announced a fast in protest, one that lasted only six days before a compromise was agreed upon, yet which did more damage to his health than any of his previous fasts. And throughout the six days, India hung on his every breath.

Whether because of his evident physical weakness, or the disappointment brought on by the failure of the Round Table Conference, Gandhi made plans to remove himself from politics. While still in prison, he decided to devote himself again to his "constructive work," as he called it, of improving the daily lives of his fellow Indians. To prepare for this, in 1934 he announced another fast, for self-purification–and this time the British, terrified at the consequences if he were to die in prison, released him.