Proving grounds

President Harry S. Truman (inside windowed shelter, third from the left) and other unidentified dignitaries attending a weapons demonstration at Aberdeen Proving Ground in Maryland.

President Harry S. Truman delivering a speech during his visit to Aberdeen Proving Ground in Maryland. From left to right: unidentified Army officer; Secretary of the Army Frank Pace; Major General Edward MacMorland, Commanding Officer of Aberdeen Proving Ground; President Truman; unidentified military officer; General J. Lawton Collins.

President Harry S. Truman (standing on the ground, looking up at camera) and other unidentified persons standing next to a T-41 "Walker Bulldog" tank, named after the late General Walton Walker, during a visit to Aberdeen Proving Ground in Maryland. Standing on the stepladder is Secretary of the Army Frank Pace. All others are unidentified.

Demonstration of a tank traveling through water at Aberdeen Proving Ground. President Harry S. Truman (not pictured) attended this demonstration.

Demonstration of a tank traveling through water at Aberdeen Proving Ground. President Harry S. Truman (not pictured) attended this demonstration.

President Harry S. Truman peers down into a T-41 "Walker Bulldog" tank, named after the late General Walton Walker, during a military demonstration at Aberdeen Proving Ground in Maryland. Armed forces officers on the ground are unidentified.

Demonstration of a tank traveling through water at Aberdeen Proving Ground. President Harry S. Truman (not pictured) attended this demonstration.

President Harry S. Truman (foreground, first on right) with unidentified Army officers throwing a switch during a demonstration of military hardware at Aberdeen Proving Ground in Maryland.

President Harry S. Truman (standing on stepladder) and other unidentified military officers inspecting a tank during a military demonstration at Aberdeen Proving Ground in Maryland.

President Harry S. Truman and other dignitaries during a military demonstration at Aberdeen Proving Ground in Maryland. Front row, left to right: Major General Edward MacMorland, Commanding Officer, Aberdeen Proving Ground; President Truman; General J. Lawton Collins. Second row: Averell Harriman (second from right) and Secretary of the Army Frank Pace (right). Third row: General Harry Vaughan (right). Admiral Robert Dennison is in the row behind General Vaughan, second from the right. All others are unidentified.