A year ago the American pavilion at the Shanghai Expo was a vacant lot, with the skeletons of other national pavilions rising all around it. World expos are a chance for nations to demonstrate their power and prosperity -- the United States has hosted them in San Francisco, St. Louis, Chicago, and New York multiple times. A staple of every county fair, the Ferris Wheel, was invented for the 1893 Chicago World's Fair in an effort to rival the Eiffel Tower built for the Paris Universal Expo four years earlier. This is China's first World's Fair, projected to attract 70 million Chinese and many millions more from all over the world. The America they will see when they visit the USA Pavilion, miraculously erected in one year due to the hard work of the State Department and many private citizens and the generosity of leading U.S. corporations, is a rainbow of diversity and a celebration of community. From student ambassadors speaking fluent Mandarin to truckdrivers and farmers learning to say Nihao, we come off not as an arrogant superpower but as warm, welcoming ordinary people who reflect the world and have the energy and determination to build a better one.