NOAA has a [Historical Map & Chart Collection][charts] with free
downloads of high resolution scans of all sorts of historical maps and
charts.  For example, [George Vancouver's 1791 “Chart Shewing part of
the Coast of N.W. America”][vancouver].

[charts]: http://historicalcharts.noaa.gov/
[vancouver]: http://historicalcharts.noaa.gov/historicals/preview/image/VAN520

[[!tag tags/fun]]