Tobacco use remains the single largest preventable cause of disease and premature death in the U.S., yet more than 45 million Americans still smoke cigarettes. However, more than half of these smokers have attempted to quit for at least one day in the past year. As of 2010, there were also 13.2 million cigar smokers in the U.S., and 2.2 million who smoke tobacco in pipes.. (Courtesy graphic)