Short answers, pulled from the story.
People living in present-day Romania boiled spring water to extract salts around 6000 BC. This process created briquetage, a method used by Neolithic people of the Precucuteni Culture at the Poiana Slatinei archaeological site near Lunca.
Solnitsata in Bulgaria became Europe's first city as a salt mine providing the Balkans since 5400 BC. It functioned as a major extraction point during this early period of European history.
Mahatma Gandhi led a crowd of 100,000 protestors on the Dandi March or Salt Satyagraha in 1930. They made their own salt from the sea as a demonstration of opposition to the colonial salt tax.
The World Health Organization recommends adults consume less than 2,000 mg of sodium daily. This amount equals 5 grams of salt contained within that limit.
The oppressive salt tax in France caused the French Revolution and remained until 1946. Napoleon reimposed the tax after its repeal to pay for his foreign wars before it was finally removed.