File:Boston 1842.jpgMap of Boston in 1842. Source: http://www.lib.utexas.edu/maps/historical/boston_1842.jpg License: Public domain according to http://www.lib.utexas.edu/usage_statement
File:Boston 1842 PembertonHill area.jpgMap of Boston, showing area of Pemberton Hill, 1842. Derived from Wikimedia Commons file: Boston_1842; cropped to show detail. English determination method: