Organization charts for government departments are often included in the About Us section of the department's web site. This information is also included under information about leadership.

ProQuest Congressional
This resource provides congressional publications on key American public policy issues including foreign affairs, crime, national security, transportation, the economy, commerce, public health, the environment, and education. It also includes the full text of proposed legislation and its status in the legislative process and the full text of recently signed law. Lexis Nexis also provides information about current members of Congress and Congressional committees, and features a Hot Topics section.

USA.gov
http://www.usa.gov
Called the U.S. government's official web portal, this site allows usrs to search for information across all federal agencies, as well as at the local and state levels.

Congress.gov
https://www.congress.gov/
This site from the Library of Congress provides legislative information including bill tracking, presidential nominations, the text of committee reports, and other information.

Census Data
https://data.census.gov/cedsci/
The Census, conducted every ten years, gathers demographic and economic information about the United States.

US Census Research Guide
This guide provides information about searching the Census for information.