At the federal level, there are numerous agencies which maintain fire services:
BLM (Bureau of Land Management)
NFS (National Forest Service)
NPS (National Park Service)
FEMA (Reserve engines, usually staffed with state or local firefighters, used for large crises)
There are three branches of government: the executive branch, the judicial branch, and the legislative branch. The Department of Justice belongs to the executive branch.
executive
US TREASURYExecutiveLegislativeJudicial TeTe
The US Tax Courts are part of the Legislative Branch of government, but support the IRS and the Department of the Treasury, which are part of the Executive Branch of government.
The FBI is part of the Department of Justice, which is part of the Executive Branch of the United States federal government.
executive
US Department of Justice
All of these departments belong to the executive branch.
The State Department is part of the executive branch of government. They are responsible for executing the President's and the countries foreign policy and managing relations with other countries.
BATFE is part of the United States Department of Justice.
The word "department" can be a noun. It refers to a specific division or branch of an organization or government.
The United States Department of the Treasury is in charge of proposing new currency. It is part of the Executive Branch.