To see precise values, hover your mouse cursor over the red graph trace. (However, the ice core values are less accurate than the Mauna Loa measurements.)
1958-present data is from ftp://aftp.cmdl.noaa.gov/products/trends/co2/co2_annmean_mlo.txt & ftp://aftp.cmdl.noaa.gov/products/trends/co2/co2_mm_mlo.txt (measurements at Mauna Loa Observatory, HI).
1850-1958 data is from http://data.giss.nasa.gov/modelforce/ghgases/Fig1A.ext.txt (ice cores).
1840-1850 CO2 data is from http://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/law/law_co2.txt (Law Dome ice cores, 75 year smoothed).
We also have a similar graph for methane (CH4), and a combined graph with both CO2 and CH4.