yes, salt it needed for good animal husbandry, and for making cheese--and cheese is easier to transport long distances, (ie to NYC))than milk. salt is also added to butter to preserve it. (more was added in the past before refridgerations was commonly available.)

the book Salt, a world history points out that cheap readily available salt was just another one of the commodities that the northern states were rich in, and the souther states lacked when it came to the american civil war.

cheap salt meant it was easy to preserve meats (hams and corned beef, and other foods.(and since an army marches on its stomach...