Afriterra Foundation provides historical maps of Africa
American Geographical Society Library (AGSL) Digital Map Collection contains over 500 maps from the 15th to the 20th century.
Massachusetts Historical Society online maps include twenty-four manuscript maps of local towns and counties dating from 1637-1809 and eight iconic printed maps of Massachusetts and Boston.
For local maps, the Boston Planning and Development Agency webpage includes data, maps and aerial photographs.
The World Bank Global Reach Map is a collection maps and data, a visual look at wealth--and poverty--distribution throughout the world.
Worldmapper: The World as You've Never Seen It has maps showing areas of interest--not country boundaries. Looking for a map showing the distribution of wealth, income, food, housing?
More statistical sources:
Analyze Boston geographic, development and demographic information.
U.S. Census Bureau, a resource for U.S. statistics.
Population Reference Bureau (PRB) "informs people around the world about population, health, and the environment, and empowers them to use that information to advance the well-being of current and future generations." Use the DataFinder to browse for data geographically and by topic.
Social Science Statistics, a subject page compiled by the Social Sciences Librarians on a variety of topics: