| Olympic medal record
|Gold||1932 Los Angeles||Team eventing|
|Silver||1932 Los Angeles||Individual show jumping|
Henry had never ridden a horse before attending West Point, from which he gradutated in 1910. However, he learned to ride incredibly well while at West Point under General Guy V. Henry, and went on to great accomplishments in various equestrian sports. Chamberlin was in active military duty in France during World War I, when he served with the 161 Brigade. It was during this time that he competed internationally for the first time, riding in the 1919 Inter-Allied Games held in Paris (the 1916 Olympics were cancelled due to the war), before returning home.
Chamberlin was assigned to Fort Riley's Horsemanship Department and went on to compete at the 1920 Olympic Games with his mount Nigra. He was then sent to Europe to train for two years, the first year at the French Cavalry School in Saumur, and the second at the Italian Cavalry School in Tor di Quinto. While in Italy, he was introduced to the forward seat, which he brought back to the United States and which now dominates the hunter and jumper scene.
Chamberlin was then sent to Fort Bliss in Texas. In 1927, he returned to train the 1928 Olympic Team, which he captained in both eventing and jumping. During this time he taught his teammates the forward seat, which was renamed by them as the "Chamberlin Seat." At the Olympics, the event team was eliminated when one of their riders missed an obstacle, despite having had the best cross-country rounds of the day. Chamberlin finished 21st individually in the event competition on Benny Grimes. In the jumping competition, Chamberlin competed again on Nigra, finishing 18th individually, and the American team placed 8th (out of 16 nations).
He later went on to compete at the 1932 Olympic Games, again riding on the event and jumping teams. He finished 4th individually on the ex-racehorse Pleasant Smiles, despite a fall on cross-country, and the team was able to clinch the first gold medal the American equestrian team had seen. In the jumping competition, Chamberlin rode the Thoroughbred Show Girl over a notoriously difficult course, and went away with the individual silver medal. A disqulification of another team member meant the Americans did not win the gold team medal as well.
Chamberlin is perhaps best known for his teaching and training ability, with Lieutenant Earl Thomson citing him as teaching him how to ride. He was inducted into the US Show Jumping Hall of Fame in 1990.
Chamberlin was also a very accomplished polo player, where he won the national 12 goal championship (1925), and 20 goal championship (1926). While at West Point, he was also known to be very good at non-equestrian sports, including boxing, football, and track.
Chamberlin wrote several books, including Riding and Schooling Horses (1934) and Training Hunters, Jumpers, and Hacks (1937).
- Dimarco, Lou. "Brigadier General Harry D. Chamberlin." Military Horse.org. 1999. Accessed 25 June 2008.
- Bryant, Jennifer O. Olympic Equestrian, A Century of International Horse Sport. Lexington, KY: Blood-Horse Publications, 2008