The pandemic H1N1 influenza that began in Mexico in the spring of 2009 spread rapidly to southern California within days and around the world within a few months. Because the genetic make-up of the new virus was novel, several months of lead-in time were required before a suitable vaccine for human use could be produced and distributed. The effort to confront the virus on the part of the World Health Organization which included almost every nation on earth and a vast array of scientists and public health officials was extensive and timely. However, it was the moderate severity of the virus itself that saved global public health from catastrophe. Because of the extensive publicity and research that occurred during the H1N1 pandemic, many lessons were learned that will be useful in confronting future influenza pandemics. A "One Health" approach to prevent, detect, and combat future pandemics is essential.