I want to start a thread for people who are interested in mapping the
US 2010 Census Data - for sharing ideas and free data sources.

My goal is to make a map of the US that shows Race at the block
level.  So I'd like to color code areas for the major race groups:
black, white, hispanic, asian, and native american.  I'm also
interested in income data - which is available down to the census
tract level.

There are several problems trying to do this with Google Maps. These
problems include

-Census Data set is very large - 200 GB for the entire summary file
1.  It'll be smaller if I filter out all the variables I don't need,
but it still is going to be huge.

-Google Maps has trouble displaying large KML files. I'd like to
convert the Tiger Shapefiles (which define the boundaries of census
tracts, block groups, etc) into KML.  This is probably feasible if I
do it for a single state and only down to the census tract level. But
if I try to do it for block groups or blocks - it will be harder.

-I could generate tiles.  But if I want to show blocks on tiles I need
to go to zoom level 14 or more.  I either need to statically generate
a huge number of tiles (to cover the entire US at zoom level 14) or do
it dynamically.  For generating static tiles I think GMapCreator looks
like the best solution: http://www.casa.ucl.ac.uk/software/gmapcreator.asp
Does around 1000 tiles/minute on my computer.

-Census Data is in a hard to use format.   The Census Bureau
recommends using a Microsoft Access tool to access it.  If you do not
need the block groups and block level data, an *excellent* resource
is: http://census.ire.org/

How can I display block level data?

For Census Geographical Areas my guess is there are around
-3000 counties
-40,000 zip codes
-75,000 census tracts (1 per 4000 people)
-210,000 block groups
-8 million blocks

If I were to use KML I think I could display counties for the entire
US map, zip codes when zoomed in to the state, census tracts when
zoomed into the state (might be slow for big states), block groups
when zoomed into a county, and blocks for medium and small counties.
To do this I'd need to generate 3000+ KML files (one for each
county).  Is there a better way?

Note: I'm using this county KML file (which you are free to use):
http://www.energyjustice.net/map/kml/county_boundaries.kml


Also: Are there any good Census 2010 data APIs?

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