The government keeps records about itself and about the country, and these are open to the public though they are not always immediately available on the Internet. The best place to start is the website for that particular governmental body. See the page on FOIA to learn about requesting records that are not readily available.
Here are some of the records you may find:
There are also a lot of records on individual members of government, government spending, legislation, and more. Look at the "Politics" tab on Resources for Reporting and at the U.S. Law & Government Information guide for more help.