Surveying populations and publishing the data requires extraordinary resources. It takes the resources of an entire country to support the effort. So, most population statistics are gathered and made available by the federal government. When you find demographic data for any area within the United States in any program or report, it probably originated in data gathered by the U.S. Census Bureau.
To find U.S. demographic data by zip code: Go to Census.gov and scroll down the page to
Access local data with QuickFacts.
The questions that the Census Bureau uses in its surveys change with each survey. The Bureau is mindful that people are interested in tracking trends, and lobbies to repeat questions from year to year, but they do not have the final say (Congress does). So some of the information will be dated. The year the data was gathered will be listed; make sure you note it along with the data.
You can also use "QuickFacts" to gather data by city and county.
To find information on your neighborhood:
Keep in mind that the Census Bureau, by law, cannot publish personally identifiable information. That means, when you get to smaller geographic areas (like a few city blocks) much of the information will be unavailable. They aren't going to publish the household income of all the people over 100 years of age - there might only be one, and then they would have published that person's personal information.
Most information should be available at the Census Tract level. So the first step in finding the data is to determine the Census Tract number. Use the Census Geocoder to find the Census tract number.
At the Census Geocoder, put in an address that is within the Census Tract of interest:
If you receive an error message make the change that the software demands. (The most common error message is that the current year is not available and you need to change the "Vintage" of the data - use the pull down menu under "Vintage" to do so).
The search results list is the geographies for which there is data available. Scroll down to Census Tracts.
That part of the list for 5500 University Parkway current-current looks like this:
Census Tracts:
STATE CODE: 06
CENTLON: -117.3395821
GEOID: 06071004512
CENTLAT: +34.1965191
COUNTY CODE: 071
TRACT CODE: 004512
AREAWATER: 0
AREALAND: 5817641
NAME: Census Tract 45.12
The tract name: 45.12 is the information you need.
Back at the Census Home Page (Census.gov) go to:
Census data covers dozen of topics across 130+ surveys and programs. Get in the weeds with more than 2.5 million tables of raw data, maps, profiles, and more at data.census.gov — the Census Bureau’s premiere data dissemination platform.
It will take you to data.census.gov. Select Advanced Search. Choose to "Filter" by Census Tract:
Drill down through California, then by county. Scroll down to select the Census Tract of interest.
The Census is topic x geography. You have determined that the geography you are interested in is Census Tract 45.12. Now decide what topic to find first.
Choose a Topic of interest (again you might need to drill down - for instance "veterans" is under "Populations and People").
Then select "Tables" from the menu at the top, and the table should display.
(If you are interested in seeing little thumbnail data sets for other Census Tracts, you can click on "Maps" instead of "Tables" and take a peek at different tracts.)