How does the GDP of the USJAN 23 2008

How does the GDP of the US today compare with that of other countries in the past?

China and India combined to produce nearly half the world's economic output in 1820 compared to just 1.8% for the U.S. Our remarkable growth since 1820 has benefited from democratic institutions, a belief in capitalism, private property rights, an entrepreneurial culture, abundant resources, openness to foreign investment, the best universities, immigration and relatively transparent markets.