In 1999, NASA showed there was no net global warming from 1866 to 1976, and that 1877 was the warmest year during that interval.
Archived version of http://www.giss.nasa.gov/data/gistemp/GLB.Ts.txt
Note that this looks nothing like Michael Mann’s hockey stick blade from 1866 to 1976. Mann shows about 0.4C net warming from 1866 to 1976.
The next image overlays the 1999 NASA data on the hockey stick graph, at the same scale normalized to the 1877 spike.