The history of crude oil prices has been cyclical at times, but these prices have mostly gone up over the past 150 years. Below is a chart with the prices. Note that the official US dollar did not come into existence until 1861.
History and Forecast of Retail Gasoline Prices in the USA - Courtesy U.S. EIA
Oil and Gas Prices Charts
The graphs and charts below show oil and gasoline prices over time. Note the upward trend with three well defined retreats below. Are we in a price retreat now? It appears so, but time will tell.
Price trends up over time
1859 - 1860 - First oil drilling and production in Pennsylvania
1863 -1864 - Civil War begins
1879 - 1973 - The average per barrel price follows the Consumer Price Index almost exactly. The CPI adjusted value of a $0.86 barrel of oil in 1879 to 1973 would be $3.95. Note that the price in 1973 was $3.89.
1973 - 1974 - The OPEC Cartel shocks prices by cutting production. First oil crisis; economies reel.
1980 - 1985 - Second oil crisis; US domestic drill rig count tops 5,000.
2000 - 2009 - Middle East instability, oil wars, peak oil begins to kick in, large scale industrial and economic growth of countries like China and India.
2012 and beyond: In the longer view, it appears that Peak Oil and politics will be the dominant controls over oil prices.