Why did Gandhiji choose to break the salt law?

According to salt law, the state had a monopoly on the manufacture and sale of salt. Mahatma Gandhi thought it was sinful to tax salt since it was such an essential item of our food. He led a march to the coastal town of Dandi, where he broke the salt law by gathering natural salt found on the seashore and boiling sea water to produce salt. This march related to the general desire of freedom to a specific grievance shared by everybody.