On October 11, 1910 Teddy Roosevelt (wiki) became the first president (well, ex-president at the time) to fly in an airplane. The Library of Congress has footage:
From the following day's New York Tribune:
The aeroplane sped quickly around the field at a height of less than one hundred feet. It made the first lap of a mile and a half before news percolated through the crowd that Mr. Roosevelt was Hoxsey’s passenger. When he swept past the grandstand he leaned forward a bit and waved his hands. The spectators seemed frightened and remained silent, watching the aeroplane intently.
The flying machine sped by and made the turn for the second lap. Hoxsey could be seen to bend over and shout something into Mr. Roosevelt’s ear. The engine cracked regularly, hurling the aeroplane forward at a speed of nearly a mile a minute, but from the ground it looked as though it were travelling much slower because it sailed so evenly and smoothly. There was not a breath of wind, and the engine did not miss fire once.Via UPI,
Here's Aviator Hoxsey's story of Roosevelt's daring trip:
"President Lambert of the St. Louis Aero club introduced me to Roosevelt. Lambert said something about my trip from Springfield. Roosevelt said he envied me. 'Here's your chance,' I said to him.
'"All right,' said Roosevelt, 'but let's not make too much fuss about it.'
"Roosevelt was on the machine before I was. He was bareheaded. A newspaperman gave him a cap and he said 'let 'er go.' We started.
"I didn't look at Roosevelt until I felt the machine wiggle. He was waving at the crowd. We were up about 150 feet.
"'Be careful not to pull any of those strings,' I warned him. He was sitting directly underneath the valve cord of the engine and the engine would have stopped had he touched it.
"'Nothing doing,' he shouted back, showing his teeth. The propeller made so much noise we had to shout.h/t Paleofuture