The facility at 3801 Nebraska Avenue has quite a history. Located five miles from downtown Washington, the site lies in the historic NW area of the District of Columbia, just across Ward Circle from the American University.

Did you know that in an effort to break WWII Japanese (and later) German codes, early cryptologists and cryptanalysts spent thousands of hours in those myriad rooms. They were codebreakers. In Feb 1943, over 1,100 men and women worked on the complex problems associated with codebreaking. By the end of WWII, there were over 5,000 persons employed as codebreakers at the Navy's Nebraska Avenue facility.

In July 1922, the U.S. Navy formally established a cryptologic element, known as the Communication Security Unit, or DNC OP-20-G; a part of the Office of the Director of Naval Communications. The unit was located at the Main Navy Building, commonly referred to as "Main Navy", 18th St. & Constitution Ave.

In October, 1928 the Navy also established a school for enlisted Navy and Marine Corps intercept operators at the Navy Department in Washington, D.C. In a specially constructed blockhouse, a classroom and eight intercept positions were erected on the roof of "Main Navy"; probably as much for the sake of privacy as for the lack of space. Student graduates became known as the "On the Roof Gang." The first instructor was Chief Radioman Harry Kidder, who had taught himself to recognize and intercept Japanese radio communications, while previously serving in the Philippines.

On 11 Mar 1935, the unit was redesignated as the Communications Security Group (CSG). This date is observed as the birth of the Naval Security Group. In Feb 1943, the CSG transferred to a new facility at 3801 Nebraska Ave. NW, Washington, DC. The facility at 3801 Nebraska Avenue was known as the Communications Supplementary Annex from Feb 1943. It was renamed NAVCOMMSTA Washington (NCSW) on 07 Jul 1948, and redesignated as the Naval Security Station (NAVSECSTA) on 21 Sep 1950.

In Sep 1950, the Communications Security Group (CSG) and the Communications Supplementary Activity Washington (CSAW), were merged to officially form the establishment of the Naval Security Group, headquartered at NAVSECSTA.

In 1994, the "Naval Security Station District" was identified as a historic property, and is listed in the National Register of Historic Places, administered by the National Park Service.

The COMNAVSECGRU headquarters staff officially moved from NAVSECSTA to Fort George G. Meade, MD in Nov 1995. NAVSECSTA was not officially disestablished until 16 Oct 1998, almost three years after the last NAVSECGRU office had moved.

Besides COMNAVSECGRU HQ, other activities that resided at 3801 Nebraska Avenue included: the Naval Computer and Telecommunications Command (NCTC), the Director, Communications Security Material Systems (DCMS), a Personnel Support Detachment (PSD), and the Naval Electronic Systems Security Engineering Center (NESSEC).

The site at 3801 Nebraska Avenue, NW is now (January, 2003) known as the Nebraska Avenue Complex (NAC), a Field Support Activity of the Naval District Washington (NDW), headquartered at the Washington Navy Yard in Washington, DC. Some of the current tenant commands are: Naval Center for Cost Analysis, Naval District Washington Public Safety, Director of Strategic Systems Programs, Office of Civilian Personnel Management, and the Navy International Programs Office.

Nebraska Avenue Complex (NAC)