Assuming that you are speaking of President Kennedy's father he was worth around $600 million at the time of his death in 1969. That's the eqivilent of around $3.3 billion dollars in 2007 money.
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16 million US dollars in 1869 would be worth $280,701,754.39 today in August 2014. The discrepancy in value is due to inflation.
1,000,000 dollars in 1900 would be worth 890,000,000 dollars in 2013. The two links below are useful tools to deterning appreciation/depreciation of a value of money over time. Who can be sure of the accuracy though?
5 pounds would be 25 US dollars back then, and the web's inflation calculator shows around thirty 2021 dollars to one 1913 dollar, so I'd guess that one Victorian Pound would be 5x30 or $150 in today's money. 500 pounds would be 500x150$ or 75 thousand dollars today.
£2,000,000
fifteen thousand dollars
With inflation it would be worth £1,679.00 today.
With inflation it would be worth £1,679.00 today.
Using inflation, £6,000 in 1903 would be worth £480,256 in today's money.
£10 in 1972 would be worth £97.50 in today's money, allowing for inflation.
It would be worth around 9 million dollars based on inflation.
Using the rate of inflation, $1m US Dollars in 1955 would be worth $8,039,693 in today's money.
Because of inflation it would be worth about $25853.94 but this is only an estimate inflation rates for decades were based on what farmers were payed which could fluctuate for a number of reasons.
$900.00 from 1965 would be worth $6,229.30. In the time period there was about a 4.4% annual increase from inflation.
246388651.64 Source: http://www.westegg.com/inflation/infl.cgi
About $18666565.67 Figures from using inflation calculator thru 2010.
Given the inflation rates since 1978 - about 12 pence !
$25,000.00 in 1836 would be approximately $1212.47 today. I used online inflation calculators dating back to 1800.