How can I travel to ICE or DHS headquarters? [closed]

Most offices dealing with national security or intelligence are closed to the public, and you are only admitted if you have an appointment with someone who works there and undergo a level of screening appropriate to the facility you are visiting. You may not make it past the front lobby, and in some cases past the front gate.

That said, government offices, like private ones, are workplaces, and if even members of the public could enter the office buildings unhindered, I am not exactly sure what you would get out of the trip. Consider that "headquarters" is not necessarily where the most representative or most important work takes place, especially for an agency like ICE where most activity is at field locations and administered from field offices. Most of the Pentagon, and CIA headquarters, and so on is filled with cubicles and conference rooms no different from any corporate office or academic administration building.

That said, education of the public regarding an agency's mission is a legitimate interest in the eyes of most offices, or at least in the eyes of their public affairs officers. Some, like NASA or the Drug Enforcement Agency or the Department of Agriculture, have museums or visitors centers specifically devoted to that purpose. In other cases, tours can be arranged for groups of visitors if requested in advance, as for the Pentagon.

My recommendation therefore would be to contact the appropriate public affairs office to see how they might accommodate someone doing research for a school project. Agency contact information is linked from the DHS website. If you know someone who works for one of the offices within DHS, you can also inquire with them about rules regarding visitors. It's possible that there are low-security offices where you would be able to visit a friend, but you might still require screening beforehand.