The Maps Mania blog had an interesting post about Mapping the Growth of America (link). I decided to download the source data from this link to generate this animated GIF.
The Historical Settlement Data Compilation for the US (HISDAC-US) includes a Built Up Area (BUA) layer that provides the year of initial development for 250 meter grids in 5 year increments from 1810 until 2015. These 150 meter grids are equivalent to 15.44 acres.
Here is a link to a PDF of these maps which lets the user progress through the maps at there own pace.