This May, thousands of Americans will bet on the Kentucky Derby, the most heavily-wagered horse race in the U.S. On this episode of BackStory, the Guys explore the history of gambling in America, from 18th century horse racing to cards, lotteries and the birth of Las Vegas. We’ll hear how lotteries help raise money for the Virginia colony, and when horse racing was America’s most popular spectator sport. We’ll also learn how gambling, once outlawed in much of the U.S., has also been a major source of revenue for cash-strapped communities.