Mason & Hanger History

The longest operating American A/E Firm, with a rich history of supporting the U.S. Federal Government.


Claiborne Rice (C.R.) Mason born in Chesterfield County on the outskirts of Richmond, Virginia.

Claiborne Rice (C.R.) Mason photo



Mason Syndicate founded in Virginia by C. R. Mason focused on railroad construction.

Virginia railroad construction



Claiborne Rice (C.R.) Mason, President 1827-1885


1861 - 1862

C. R. Mason joins the Confederate Army and becomes a road and bridge builder for General Stonewall Jackson. General Robert E. Lee refers to Mason as “An experienced bridge builder.”


Date Unknown

Virginia Central locomotive, the C.R. Mason, was used to transport Stonewall Jackson’s troops.

Virginia Central locamotive, The CR Mason used during Civil War



C. R. Mason is faced with rebuilding his company. After four years of Civil War, his estimated $1 million pre-war wealth is almost gone. He begins by helping restore the Virginia Central Railroad.

civil war bridge



Renamed to Mason & Hoge.



Construction of Rays Hill Tunnel for the Southern Pennsylvania Railroad – C.R. Mason’s last major project.

rays hill tunnel



Mason & Hoge relocates to Kentucky.



Horatio P. Mason, President 1885-1905

Horatio P. Mason



Mason & Hoge completes it’s portion of the largest construction project in the world, the Chicago River Reversal, ahead of schedule. The project receives two designations from the A.S.C.E., Monument Of The Millennium and Historic Civil Engineering Landmark.

1896 Chicago River



Mason & Hoge receives first project for the U.S. Military. Louisville District COE: Lock & Dam #10 on the Kentucky River.

lock and dam



Harry B. Hanger,President 1906-1925

Harry B Hanger headshot



Mason & Hoge renamed to Mason & Hanger.



Moodna Siphon Tunnel. One of two deep pressure tunnels Mason & Hanger built as part of the Catskill Aqueduct System, New York, through nine miles of solid rock. A.S.C.E. designates Historic Civil Engineering Landmark

Catskill Aqueduct



Mason & Hanger begins last railroad project; Cumberland Valley (C. V.) Railroad in Maryland.



U.S. enters WWI in Europe. Mason & Hanger awarded first of five wartime contracts to construct Camp Zachary Taylor, Louisville, Kentucky. Over 1700 buildings completed in less than 3 months.

camp zach taylor



Silas Mason oversees Old Hickory Powder Plant contract in Tennessee. For the 25,000 workers needed to complete the job, Mason & Hanger constructs the city of Old Hickory to accommodate a population of 100,000 . . . in only eight months.

Old Hickory Power Plant



Mason & Hanger constructs Hotel Lafayette, Lexington’s second skyscraper.

Hotel Lafayette



The Silas Mason Company founded as a subsidiary to assist in the New York Subway work.

Pictured below: Mason & Hanger Compressed Air Worker Pin
– identifying a hospital at 94 Furman St., Pier 6, in
Brooklyn, NY [via Fulton Street – East River- Cranberry St. Tunnel], as the designated location to transport the worker in the event of an emergency.

Lincoln Tunnel MH Pin Long Island



Silas B. Mason, President 1926-1929

Silas Mason photo



Silas Mason, interested in the Thoroughbred horse racing industry, pledges a sum of money to help establish Keeneland Race Track in Lexington, Kentucky.

Winning horse at Keeneland horse track



Construction begins on the first of three tubes of the Lincoln Tunnel for the New York Port Authority.

Lincoln Tunnel construction in New York



Construction of the Grand Coulee Dam on the Columbia River, in Washington State. The dam itself would cover 35 acres, sit on a 500 foot base, rise to 550 feet (over 34 stories) and contain over 15.5 million yards of concrete. Mason & Hanger also constructs Mason City to accommodate the 6,000 plus workforce.

coulee closeup view



Mason & Hanger completes construction of the New River Ordnance Plant in Virginia and begins construction of the Louisiana Ordnance Plant in Louisiana.

louisiana ordnance plant



Mason & Hanger begins operation of the Atomic Energy Commission’s Burlington Plant in Iowa, the AEC’s first production plant for high explosive components for nuclear weapons.

atomic energy commission logo



Mason & Hanger begins operation of the Iowa Ordnance Plant in Burlington, Iowa and Cornhusker Ordnance Plant near Grand Island, Nebraska.

Vintage Iowa Plant D&Z Badges



Mason & Hanger begins design for the Nevada Nuclear Weapons Test Site.

Nevada nuclear test site



Serving as Architect-Engineer for AEC’s Nevada Test Site for nuclear weapons, Mason & Hanger develops some of the nation’s leading technologies for designing structures to resist dynamic loading. The structures include 300’ and 500' detonation towers and Gravel Gerties.

Gravel Gertie



Mason & Hanger and The Silas Mason Company merge and become Mason & Hanger - Silas Mason Company.

W. Arnold Hanger, President 1955-1976

Arnold Hanger in 1955



Mason & Hanger - Silas Mason Company begins operation of the Atomic Energy Commission’s Pantex Plant, outside Amarillo, Texas, the AEC’s second production facility for nuclear weapons.

pantex plant



After WWII delays construction, the third tube of the Lincoln Tunnel is completed and opened.

Lincoln Tunnel crowd



Established a new A/E office in Jacksonville, Florida for a design contract with Thiokol Chemical Corporation to build a manufacturing plant and testing silo for solid propellant rocket motors. Thiokol’s motor was the first stage, or booster, for the Saturn rocket, used to launch the manned Apollo spacecraft into Earth orbit.

thiokol rocket motor



Mason & Hanger designs first hardened launch complexes for the Titan I ICBM’s at Vandenberg A.F.B. and four other operational complexes. Resultant construction cost of $350 million.

Titan ICBM


Mason & Hanger provides experimental design of Zero Plutonium Reactor near Idaho Falls, Idaho.

Plutonium Reactor



Mason & Hanger acts as Owner’s Representative on the 23 story Kincaid Towers in Lexington, Kentucky and would move its home office there 23 years later.

Kincaid Tower in downtown Lexington, Kentucky



Law Enforcement Training Center, at Eastern Kentucky University in Richmond, Kentucky.

law enforcement training center at Easter Kentucky University



Mason & Hanger forms the design arm of the company, Mason & Hanger Engineering, which becomes The Mason & Hanger Group in 1998.


Mason & Hanger, acting as Owner’s Representative, finishes the $45 million Civic Center in downtown Lexington. This complex includes the 23,000 seat Rupp Arena, a shopping mall, convention hall and a hotel. Also included in the contract is restoration of the Victorian-era Lexington Opera House.




Modernization of the Lexington Blue Grass Airport, including construction of a new terminal building. Mason & Hanger provides complete construction management for the project.

bluegrass airport



High Explosives Application Facility Lawrence Livermore National Laboratory, California. 111,000 SF facility was labeled as “The most advanced facility of its type in the free world”.

High Explosive Application Facility Exterior



Applied Science Technology Center at the University of Kentucky. This $15 million addition to McVey Hall connects the Robotics and Civil Engineering buildings, and provided lab & research facilities for research students.

Tech center at the University of Kentucky



Mason & Hanger is awarded a nationwide Army Reserve Contract, and starts a series of new large facility design and renovations, that continues to this day.

1995 Army Reserve Medallion Logo



General Instruction Facility, at Ft. Leonard Wood, Missouri. This $63 million project was the Army’s largest 4th round BRAC project. Mason & Hanger received an overall ACASS Rating of “EXCELLENT”.

General Instruction Facility exterior



Mason & Hanger joins the Day & Zimmermann family. D&Z acquired Mason & Hanger.

Day and Zimmermann logo



Law Enforcement Training Center, addition at Eastern Kentucky University, Richmond, Kentucky.

Law Enforcement training center exterior



Command & Control Headquarters 101st Air Assault Division, Ft. Campbell, Kentucky.

Command & Control Headquarters 101st Air Assault Division exterior



Battle Area Complex Schofield Barracks, Oahu, Hawaii. The $29 million BAX is the cornerstone range at Schofield Barracks. Supporting both mounted and dismounted infantry platoon “live fire” operations with computer driven fully automated targets and scoring from the Range Operations Center.

battle area complex schofield



Mason & Hanger designs the Special Operations Forces (SOF) Aquatic Survival Training Facility at Ft. Campbell, Kentucky which allow aircrews to remain qualified in over-water survival equipment operations and life-saving emergency procedures.

Aquatics helicopter



Strategic Weapons Facility Pacific, Security Upgrades to Naval Subase KITSAP in Bangor, Washington. With a construction cost of $30 million, the design includes: Entry Control Facilities, Emergency Generator Buildings, Security Force Facility and a Waterfront Enclave Fence.

Naval Subase KITSAP


2009 - 2013

Mason & Hanger designs the Counter Terrorism Operations Training Facility (CTOTF) Urban / Suburban Training and Forensic Science Training Complex (FSTC) at Glynco, Georgia for the Federal Law Enforcement Training Center (FLETC). These facilities serve as an interagency law enforcement training organization for more than 80 federal agencies and also provide services to state, local, tribal and international law enforcement agencies.

Counter Terrorism training facility


2010 - 2013

In response to the attacks on the World Trade Center, Mason & Hanger designs a state of the art training facility for the Asymmetric Warfare Group at Ft. A.P. Hill, Virginia.

Asymmetric Warfare Group building



Mason & Hanger receives a National Engineering Excellence Honor Award from The American Council of Engineering Companies (ACEC) for the AWG project.

ACEC Award



Mason & Hanger purchases architectural and engineering firm, Hankins Anderson (H&A) with offices in Richmond and Virginia Beach, Virginia to expand mission solutions supporting the design of secure, mission-critical facilities.

Hankins Anderson graphic



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Mason & Hanger to celebrate the company's 200 year anniversary, as the oldest American A/E Firm, with a rich history of supporting the U.S. Federal Government.

200 years graphic


Download Mason & Hanger's historic timeline.