answer:There’s quite a bit of variation in the poll numbers. According to this, a 200 Zogby poll of 968 participants found that 0.9% were vegan. According to this, a 2002 Time/CNN poll estimated that 0.2% (591.468) of Americans are vegan. According to this, a 2003 Harris poll of 1031 participants found that 1.8% were vegan. The latest poll I found, and the one with the largest number of participants, is this 2008 Harris poll conducted for Vegetarian Times. It found that of 5050 respondents, 0.5% were vegan. That would translate to about 1 million Americans.