Before the dollar bill we all know and use today, paper money in the United States used to have amazingly detailed art called banknote vignettes (they're detailed not necessarily for the sake of art, but mainly for security measures by making them harder to counterfeit).
BibliOdyssey has many wonderful examples of these banknotes vignettes, though my favorite is the angels and cherubs joyously caressing the "20" in the 19th century paper money above (and so they should caress that twenty - it's purchasing power must be something like a few hundred bucks of today's dollar!)
Current data is only available till 2009. In 2009, the relative worth of $20.00 from 1820 is:
$378.00 using the Consumer Price Index
$450.00 using the GDP deflator
$5,120.00 using the unskilled wage
$11,900.00 using the Production Worker Compensation
$12,700.00 using the nominal GDP per capita
$406,000.00 using the relative share of GDP
Data for consumer bundle only starts in 1900.