Forbes Brings you St. Patrick's Day In The U.S. By The Numbers 60 percent of Americans will celebrate 13 million glasses of Guinness will be sold (worldwide) Roughly 3.65 million cases of Irish whiskey will be consumed in the U.S. The average person will spend $39.65 Total spending is expected to reach $5.92 billion The top 3 most Irish cities (Boston, Middlesex County and Peabody) are all in Massachusetts.