An excellent interactive website for mapping colonial demographics can be found at: 
http://www.geoamericas.com/view_maps/standards_organization.asp#us_era_1  
By selecting the Flash Interactive button on:

 Population & Demographics (1650-1990)
Colonial Demographics c. 1780

the viewer may see different aspects of colonial America in 1780. These include ethnic distribution, the economy: agriculture and industry, and the colonial road network.  These may be viewed separately in layers, or altogether. 

An outline map of Colonial America in 1776 may be copied and printed from the website http://www.eduplace.com/ss/maps/historical.html . 

Using these two sites together students may complete their own colonial demographic assignments.