en.wikipedia.org/wiki/Wright_Flyer

The Smithsonian’s National Air and Space Museum says the U.S. government purchased its first military aircraft on August 2, 1909, and that the Signal Corps officially accepted the Wright airplane on that date. A U.S. Air Force history page likewise states the Army formally accepted the airplane on August 2, 1909, designating it Signal Corps Airplane No. 1.

So the article’s statement is incorrect in two ways:

1. June 3, 1909 was not the date the aircraft became the first military airplane; it was the date the Wrights returned to Fort Myer with a new airplane to continue demonstrations.
2. The status of "world's first military aircraft" followed the official acceptance/purchase on August 2, 1909, not "successful tests on June 3."

The quoted numbers are real, but they apply to 1914, not to 1917.

A National Park Service history of U.S. aviation in World War I explains that when the war began in Europe, the United States had "only six airplanes, and fourteen trained pilots" available. The same NPS article then states that when the United States entered the war in April 1917, the Aviation Section of the U.S. Army's Signal Corps had about 200 airplanes.

An official U.S. Air Force history page similarly says that at America's declaration of war on April 6, 1917, the Aviation Section had 250 airplanes and 1,200 officers and men.

So the article incorrectly assigns an early-war 1914 statistic to the very different situation in 1917.

Official museum and National Park Service sources list the 1903 Wright Flyer’s height as 9 feet 4 inches (2.8 m).

The Smithsonian’s object record for the original aircraft gives the dimensions as Height: 2.8 m (9 ft 4 in), and the National Park Service page on the Wright Flyer says its total height reached 9 feet, 4 inches. That directly contradicts the specification here, which lists 9 ft 0 in (2.74 m).