Maps Websites

The first two categories give you websites which can lead you to lots of interesting maps. Try to focus on one location at a time (e.g., country, state, county, city, etc.).  The last three categories give other interesting websites if you are dealing in Rural, Urban, or European locations

“Gateway” Websites

http://www.familyhistory101.com/maps.html
Has excellent historic maps and atlases, along with the “boundary change” files we normally use.

http://www.maphistory.info/index.html
This website is maintained by Tony Campbell, the former Map Librarian for the British Library in London.  It is a lot like a Cyndi’s List for maps..  US and International.

http://www.reisenett.no/map_collection/map_sites/hist_sites.html
Another website which lists many different maps available for free on the internet.  Much overlap with MapHistory, but better organized.  US and International.

http://oddens.geog.uu.nl/index.php
Interesting website that is no longer maintained (which means lots of broken linkages), but may contain some useful linkages of European interest.

http://maps.bpl.org/
Boston public library site.  Very good for New England and early maps.

And don’t forget Cyndi’s List (www.cyndislist.com) and the FHS Wiki site (https://wiki.familysearch.org/en/Main_Page, then search Maps)

Great map websites

http://memory.loc.gov/ammem/gmdhtml/gmdhome.html
Library of Congress (American Memory) site.  Lots of US maps.

http://www.lib.utexas.edu/maps/historical/index.html
University of Texas website with lots of US maps.

http://www.davidrumsey.com/
Historic and interesting maps.   Mostly North and South America, some International.

www.google.com/maps
Current day mapping with Google.  Includes regular street maps, topography maps, and street shots for many homes.

http://maps.nationalgeographic.com/maps
Similar to Google with the Geographic maps.

Rural Mapping

Another interesting set of maps come from old Atlases.  There is an 1895 atlas online which can be tracked both by state and by county at http://www.livgenmi.com/1895/

I have always loved the Quadrangle maps from the USGS. 
Current maps can be found at www.mytopo.com/maps
Old quadrangle maps for 14 states can be found on-line at: http://historical.mytopo.com/

In rural areas the most useful maps are land plats.  (A plat map is a map of each piece of land registered with the local political authority and its ownership).  These are called cadastral maps.
For most of the US, one of the best sources is the BLM files.  These give the locations for the land patents in the states that were not the first 13 colonies.  To find a site for an ancestor, go to the primary BLM website search page: http://www.glorecords.blm.gov/search/default.aspx
note that you can often retrieve additional information besides the exact location of the patent. 

Another site for relevant areas is the Hotchkiss maps at the Library of Congress.  These are mostly military maps from the Civil War. http://memory.loc.gov/ammem/collections/maps/hotchkiss/

Urban Mapping

Understanding census records for large urban areas can be difficult.  There are two websites that have information census records.
For 1900-1940, Steve Morse (www.stevemorse.org) has information on census Enumeration Districts (ED).  He also has a handy conversion guide for knowing when street names have changed.
There is also a website which identifies Census Finder maps located elsewhere on the net
http://www.censusfinder.com/county-maps.htm

Whenever available, city Directories can be very useful for understanding urban areas (http://www.freegenealogytools.com/2009/10/searching-free-online-historical.html)
This site both has some directories and also has locations you can go to for additional directories.

Fire Insurance Maps (almost all are Sanborn Insurance maps) were used around 1900 to record properties in most major cities: http://www.freegenealogytools.com/2009/09/free-sanborn-fire-insurance-maps-good.html.  They are very detailed.

Panoramic maps (birds-eye maps) of smaller cities can be found at the Library of Congress
http://memory.loc.gov/ammem/pmhtml/panhome.html

Europe

One of the best introductions to European maps can be found in the FHS Wiki collection. 
https://wiki.familysearch.org/en/Main_Pagehttps://wiki.familysearch.org/en/Main_Page by searching on the word “Maps”.

Some European countries have Directories on file.  You can go to the city directory website mentioned above for more information.  UK directories can be found at
http://www.historicaldirectories.org/hd/d.asp

In most European countries you can find Surname maps for where those with a given surname are located.  This can give you a sense of where your ancestors may have lived.  Federation of Eastern European Family History Societies at www.feefhs.org has interesting maps.  In some cases this includes surname maps.