Explain the importance of “salt March” of Gandhi as a symbol to unite the nation?

Mahatma Gandhi found in salt a powerful symbol that could unite the nation. On 31 January 1930, he sent a letter to Viceroy Irwin stating eleven demands. Some of these were of general interest; others were specific demands of different classes, from industrialists to peasants. The idea was to make the demands wide-ranging, so that all classes within Indian society could identify with them and everyone could be brought together in a united campaign. The most stirring of all was the demand to abolish the salt tax. Salt was something consumed by the rich and the poor alike, and it was one of the most essential items of food.