Drunk driving has been considered a crime in the United States since the early 1900s. However, the legal limit for blood alcohol concentration (BAC) and the penalties for driving under the influence (DUI) have varied over time and across states. In 1938, a scientific advisory panel recommended a BAC limit of 0.15% for drivers, and by the 1950s, most states had adopted this limit. In the 1980s, the federal government began incentivizing states to lower the BAC limit to 0.10% or lower, and by 2000, all states had adopted a 0.08% BAC limit. Penalties for DUI have also become more severe over time, with many states now imposing fines, license suspensions, and even jail time for offenders.