Historical crude oil prices going back to 1946 are published on Macrotrends.net, as of 2015. The U.S. Energy Information Administration offers spot prices on crude oil in dollars per barrel for the current market and historical data back to 1986.
Macrotrends.net offers historical prices and allows for the comparison of real and nominal prices on a month-by-month basis. Prices calculations on the site use the base for the most recent month and Consumer Price Index inflation figures.
The U.S. Energy Information Administration lists oil products by type and geographical area, including crude oil, conventional gasoline, regular gasoline, No. 2 heating oil and No. 2 diesel fuel. It also offers history for kerosene-type jet fuel and propane. Periods are searchable by day, week, month and year.