The changing map of Illinois

For the first several years of the project, IECAM used the same map of Illinois in its online database. Beginning with the early care and education data for FY2011 and the demographic data for 2009, IECAM modified its online database and GIS map pages to use a different map each year.

The reason for this is simply that—although most residents may not be aware of this—the map of the state of Illinois changes every year. While the state as a whole does not change, every year there are a number of municipalities, townships, and school districts that are created, eliminated, merged, or split, or that change their name. And every 10 years, the district maps change for the state legislature and the federal congress. This latter change occurred with the 98th Illinois General Assembly and the 113th U.S. Congress that were seated in Springfield and Washington in 2013.

In the online database, search results present data for whatever areas exist, and only the areas that exist, in a selected year. Therefore, for example, if you’re searching by municipality for 2012 and a municipality was incorporated only in 2013, you will not find that municipality in the 2012 data. Another example: If you search for data in Monroe County by townships (called precincts in that county) in 2007 or 2008, you will find 27 precincts; if you search in 2009 or later, you’ll find 37 precincts in the county’s completely reorganized township structure.

What maps does IECAM use?

IECAM uses the TIGER maps from the U.S. Census Bureau. These maps are produced for every year and include any changes to geographic regions (townships, municipalities, school districts, etc.) for the year.

When does IECAM update its maps?

The Census Bureau typically produces its map for a year at the very end of the year. For example, the Census Bureau’s 2014 TIGER map was released near the end of 2014. However, the Census Bureau does not release all the data for small regions for a given year till much later. For example, some data for 2014 by township or municipality was not released until late in 2015 or early in 2016. When the data for a given year are released, then IECAM processes the data by the TIGER map for that year.

Why does IECAM not have data for the current year?

Concerning data on early care and education services, IECAM receives these data from the state agencies involved with those services. The data for a given fiscal year (FY) are received sometime during the following FY. Thus, data on early care and education services for a given FY (e.g., FY2015) typically appear in the IECAM online database near the end of the following FY (e.g., FY2016).

Concerning demographic data, as noted above, the Census Bureau releases its final and complete data for a given year between 1 and 2 years (depending on the geographic region) after the target year. For example, demographic data for 2014 appeared around the end of 2015 and beginning of 2016.