Explore spatial data

Examine the map and legend

Publicly available data and maps can be found in the ArcGIS Living Atlas.

  1. In a browser, go to the Predominant Generations in the United States web map.

    This map highlights the predominant generations that make up the population of the United States. The predominant generation is the generation with the largest population compared to the other generations in a given area.

  2. Examine the legend.

    Legend for the map

    Each generation is represented by a different color. For example, the baby boomer generation is purple, Generation X is blue, and the millennial generation is teal.


    Demographic data is updated periodically, so the data values you see may differ from those specified in the lesson.

  3. Examine the map.

    At this zoom level, you only see purple, teal, and green United States counties. It appears that baby boomers (in purple) are the predominant generation in most counties, with millennials (in teal) and Generation Z being the predominant generations in fewer, but still a notable number of, counties.

    Notice the different sizes of symbols on the map. The symbol size shows the sum of the generational categories—that is, the total population in each county. For example, you can see several large symbols in Southern California representing counties with over 1,500,000 people.

Use bookmarks and pop-ups

You want to launch your new luxury travel services in a city that has a predominance of baby boomers. Your company has agency locations in the Los Angeles, Washington D.C., and Chicago areas. To help you decide which one would be best for launching the new services to baby boomers, you'll explore the map using bookmarks and pop-ups.

  1. Click the Bookmarks button and choose Los Angeles.

    Bookmarks button with list of places and a green box surrounding Los Angeles

    The map zooms to the area surrounding Los Angeles. At this zoom level, the generational population data is broken down by census tract area. United States census tracts divide state counties into smaller geographic areas, which are useful for revealing local spatial patterns. You can see that millennials are the predominant generation in most of the census tracts around Los Angeles.

    Map zoomed to Los Angeles

  2. Zoom in one level and pan as needed to center the map around Los Angeles.

    Your travel agency is located west of the Harbor Freeway near the Hollywood Freeway, which is surrounded by teal (millennial) census tract areas.

  3. Click the large teal tract near the intersection of the two freeways, and take some time to review the pop-up information.

    Pop-up for Los Angeles tract showing counts for all generations and predominance of millennials

    Millennials are predominant by a significant amount, with a population of over 3,000 compared to a baby boomer population of 850.

  4. Click other nearby census tracts to view their pop-ups.

    There is a similar pattern of strong predominance of millennials over baby boomers and other generations.

    With the predominance of millennials over baby boomers and the relatively low population of baby boomers in tracts near the Los Angeles agency, this agency doesn't appear to be a suitable location to launch your luxury travel services.

    Next, you'll see whether Washington, D.C., is more suitable.

  5. Zoom to the Washington D.C. bookmark.

    The map zooms to Washington, D.C., and the surrounding region. It's immediately apparent that this region has mostly millennial-dominated (teal) census tracts close to the city center.

  6. Zoom in one level.

    Your travel agency is northwest of the city center, near the Potomac River. There are predominantly millennial (teal) census tracts in this area. However, they may be worth examining more closely, as their total populations are larger than 7,000, which is evident from the size of the symbols and the map's legend.

  7. Click the teal tract, Tract 110010056.00, northwest of the Washington label near the river.

    The pop-up indicates that the baby boomer population is just over 1,000, while the millennial population is almost 4,500.

  8. Click some of the other tracts in that area and note the baby boomer populations in those tracts.

    The tracts near your Washington D.C. agency have slightly higher numbers of baby boomers than those near the Los Angeles agency. Washington D.C. may be a better candidate than Los Angeles for launching luxury travel services to baby boomers. However, you want to look at your third location, Chicago, before making a decision.

  9. Zoom to the Chicago bookmark and zoom in one level.

    Most of the tracts around Chicago are teal, indicating a predominance of millennials. However, there is a cluster of purple baby boomer tracts in Near North Side, close to Lake Michigan. This is where your travel agency is located.

  10. Click the largest purple tract (Tract 170310801.00) to see its pop-up.

    Pop-up for Chicago Tract 170310801.00 showing counts for all generations and predominance of baby boomers

    The population of baby boomers is nearly 2,000, but millennials are not far behind, with a population of about 1,800.

  11. Open the pop-up for the southernmost purple tract (Tract 170310813.00) of the four in this area.

    This tract has an even larger baby boomer population (over 2,000).

  12. Review the pop-ups for the other purple tracts. Take note of their baby boomer populations.

    When you add the baby boomer populations from these tracts together, the total number of baby boomers is significant. Most importantly, all of the tracts are in close proximity to your Chicago travel agency. It looks like you may have found the best place to launch your luxury travel services.

After only 15 minutes of work, you found a publicly available web map in ArcGIS Living Atlas, visually analyzed it using tools in Map Viewer, and answered an important business question based on your exploration. What's next?

To find more scenario-based lessons, browse Learn ArcGIS. To start, try Policy Mapping - Safe Streets to Schools. You can also visit The ArcGIS Book and The ArcGIS Imagery Book websites.

Explore ArcGIS Online on your own and discover what else is possible. A few ideas are as follows: