The United States has confidently become one of the world's largest wine-producing nations. Its reputation was founded on the global fame of Napa and Sonoma, but the U.S. is home to countless lesser known wine regions producing world class wines. While the United States has been producing wine for around 400 years, it has only been in the last 40 years that American wine really started to earn respect on a global scale. The United States is now the world's fourth largest wine producing nation (behind France, Italy and Spain).