Founded in 1908, the Federal Bureau of Investigation (FBI) was originally housed within the Department of Justice headquarters building. For its first 67 years the bureau hobbled together space within various Department of Justice buildings, including the Old Post Office. By the mid-twentieth century, the Bureau’s rapidly growing body of agents, specialists and staff were a highly visible national force. Construction of a purpose-built headquarters building finally began in the early 1960s, but was halted due to further necessary planning and design reviews. In 1977, the Brutalist style building, today named in honor of the longest serving FBI director, J. Edgar Hoover, was finally complete.