Signal Corps Specification, No. 486 was issued on December 23, 1907. The Signal Corps of the United States Army (no U.S. Air Force back then) requested, in a simple one-page document, a plane capable of carrying two men 125 miles at 40 miles an hour, remain airborne for at least one hour, and land safely.
There was a bonus provision in the contract for each miles per hour above 40, as well as a penalty for each miles per hour below if it failed to attain the target speed. If the plane provided flew no faster than 36 mph the contract would be void.
The contract with the U.S. Army, negotiated by Wilbur, stipulated for $25,000 the Wright brothers would supply that aircraft.
This was ambitious for the brothers, as the 1905 Wright Flyer carried only a pilot, and never exceeded 36 mph. In a peculiar twist, even though there was not another living soul capable of fulfilling this contract, the Army still delayed entering it because it wanted to advertise for bids.
When the negotiations were finally completed, per government rules of the era, President Theodore Roosevelt approved the contract. The Wright brothers were first.
The second military contract in aviation history came quickly on the heals of the first. In March 1908, the Wright brothers signed the first military contract with the French government. It was beginning to seem routine for the Wright brothers to be first.