The Department of Magic is the governing body of wizardry in the United States. Founded in its current form in 1789, it is headquartered in Washington D.C. There are also large regional offices of the Department in New York City, Chicago, Los Angeles, Seattle, New Orleans and Miami.

In 2012, the Department of Magic opened a regional office in Breckenridge, Colorado to act as a safe haven in the event of another wizarding war, much similar to the Battle of Hogwarts and the preceeding terrorism by Lord Voldemort (a/k/a Tom Riddle) and his Death Eaters. Additionally, the school for young witches and wizards is located in the Rocky Mountains in Colorado, strictly secluded to prevent discovery in the Muggle World. 

Prior to the American Revolution, American wizards and witches of European origin were nominally governed by the Ministry of Magic of European colonial powers, though control was generally weak. Native American magic folk owed their loyalty to their own nations and did not generally recognize the International Statute of Secrecy. During the muggle Confederation period (1776-1789), wizards and witches in each of the former British colonies attempted self-governance with varying degrees of success.

The Department of Magic is headed by the Secretary of Magic, who is also the magical liaison with the President of the United States. The Department is a member of the International Confederation of Wizards and is responsible for enforcing international agreements including the Statute of Secrecy. The Department is organized into divisions, including the Division of Magical Law Enforcement, which includes both the Auror office and the Bureau of Magical Investigation (BMI); the Division of Magical Transportation; the Division of Foreign Affairs; the Division of Commerce; the Division of Magical Education; and the Division of Magical Health Care.

The Division of Magical Education has formal oversight over Kaaterskill Academy of Magic, the oldest and primary magical school for young American and Canadian witches and wizards, as well as any other magical schools and academies.  Kaaterskill usually operates with a great degree of autonomy, depending on the personal prestige and power of its Headmaster.  However after the Great Salem Burning the Department of Magic turned its attention to Salem Witches Institute and gave it it's new name Salem Institute of Magic allowing boys and girls to enter the school. After their focus on Kaaterskill Academy of Magic was gone the school decided to combine there's with Salems giving it a fresh start. Kaaterskill Academy of Magic was then turned into a magical apartment for wizards and witches. The Department of Magic moved the students and teachers of both schools to a new location in an enchanted Forrest with many protective charms so that when Muggles get near they soon get a sense of danger then move away from the school. Salem Institute of Magic kept the Vice-Principal Arcadia Pencey as the vice-principal and Augustus Dumbledore (a relative of Albus Dumbledore) became principal. The school is now a birding school and is a castle quite like Hogwarts. The castles name is Salem Castle. The Muggles who had burned the old school was wiped of their memory and sent to jail because of an "Unnecessary Uprising" other Muggles that unaware of wizards have said to be the reason.

During the late 1970s and early 1980s, the Department was peripherally involved in the first war between the U.K. Ministry of Magic and Lord Voldemort.  During the late stages of that conflict, significant Death Eater cells organized under Hafgan, a shadowy American follower of the Dark Lord.  While never as significant threat in the United States as in the U.K., the Death Eaters carried out a number of atrocities, mainly aimed at Department officials and their families, including Aurors.  In 1981, a contingent of American and Canadian aurors disrupted a Death Eater mission to Table Mountain, Newfoundland, which contained a magical force Voldemort wished to harness.  The Death Eaters were thwarted; the only survivors of the incident were two young American aurors, Griffin and Diana Lloyd, and Hafgan himself.  When Voldemort was thwarted by Harry Potter a few months later, the American Death Eaters were quickly suppressed; many were arrested, some released from the Imperius Curse, others killed in battle with Aurors.

Ernest Dithers became the 35th Secretary of Magic in 1989.  

The US was involved in the First Wizarding War in the 1980's. Using members of the Division of Magical Law Enforcement and the BMI to act as covert militants against the dark forces plaguing the United Kingdom. During the time of the terrorism of Lord Voldemort and the deep corruption that mimicked the witch hunt of the Holocost, the United States Secretary of Magic and the US President, then William Clinton, sealed the US off from it's surrounding nations and pursued any information as to the appearance of Death Eaters or Voldemort's followers, squashing any potential of an invasion that would affect the United States and cause the Muggle-Born Holocost the US Wizarding World feared. 

On September 11, 2011, then President George W. Bush and the Joint Chiefs of Staff pleaded with the Department of Magic for assistance during the attack, the Dept of Magic willingly joined in the methods of protection by obliviating potential terrorists, and suppressing other threats. The Department used a charm in the weeks after to assist in the location of victims and also to protect the United States. To this date, the Department of Magic provides intelligence to the CIA and to the US Military regarding any leads they may have seen or discovered. This is the first Muggle and Magical alliance to have occured in the history of mankind.