The site navigation utilizes arrow, enter, escape, and space bar key commands. Left and right arrows move across top level links and expand / close menus in sub levels. Up and Down arrows will open main level menus and toggle through sub tier links. Enter and space open menus and escape closes them as well. Tab will move on to the next part of the site rather than go through menu items.
On March 1, 2003, U.S. Citizenship and Immigration Services (USCIS) officially assumed responsibility for the immigration service functions of the federal government. The USCIS was formed to enhance the security and improve the efficiency of national immigration services by exclusively focusing on the administration of benefit applications. Immigration and Customs Enforcement (ICE) and Customs and Border Protection (CBP), components within DHS, handle immigration enforcement and border security functions. [http://www.uscis.gov/portal/site/uscis/]