According to official data from both governments, the landmark event happened in late 2012. The latest data from Beijing that was revealed last month shows the total value of Chinese imports and exports was $3.87 trillion in 2012.
Last week, the U.S. Commerce Department revealed the same data for December. Adding that number to the totals for the rest of the year reveal that America bought or sold $3.82 trillion worth of goods last year.
China has been the world's largest exporter for several years already, but America is still the largest single buyer of the world's goods and services by a long shot.
China is also already the world's largest consumer of energy, and has more foreign currencies in its official reserves than any other nation.
The moment is largely symbolic, however, as by most other metrics, the U.S. economy is far larger. Indeed, in overall terms, the U.S. is still the world's economic giant. America's entire economy was worth more than $15 trillion last year, almost double that of China. China's national bureau of statistics reported last month that the country's total economy is worth more than $8 trillion.
For context, Canada's economy is worth about $1.4 trillion.