The United States Census is conducted every 10 years, and is mandated by the Constitution of the United States (if you're truly interested, you can review Titles 13 and 26 of the US Code for more information).  This census of the population - literally, a count of every person living in this country - is used to allocate Congressional seats, electoral votes, and federal funding of programs.  

It is important to remember that information collected in the census can result in redistricting.  This can directly impact (among many other things) elections, federal and state expenditure, school district boundaries, and infrastructure.

Participation in the census is mandatory for all persons living in the United States.

The US Census Bureau maintains an enormous dataset of information on its website.  By searching against this dataset, you can locate your census tract, voting district, demographic information for your neighborhood, election outcomes, etc.

You will use the information available on the Bureau's website to identify several pieces of data you will need for your project(s).

Using the American FactFinder on the Census Bureau website, find your census tract:

Click on the link under Address Search.  You will be prompted to enter a street address. 

Once you have filled in all of the appropriate fields, click GO.