We used five criteria to pick the best of the best: Olympic medals, U.S. and world records, fast times and major race wins in places such as Boston, New York, Chicago and London.
Here's who we picked and how we ranked them.
#10 Ryan Hall1 of 11
His 2:04:58 Boston Marathon in 2011 is the fastest marathon time ever recorded by an American, though it isn't considered the American record because the course is point-to-point and downhill. Hall also holds the U.S. Olympic Trials record of 2:09:02, which was held in New York City.
#9 Buddy Edelen2 of 11
Edelen set the world record for the marathon in 1963 when he became the first man to run a sub 2:15 (2:14:28). His world record was the first by an American since 1925. Later that same year, Edelen ran the third-fastest marathon in history. Though he never won an Olympic medal, he recorded seven wins in 13 races against international competition.
#8 Alberto Salazar3 of 11
Winner of three consecutive New York City marathons and one Boston Marathon, Salazar was thought to have set a new world record of 2:08:13 in 1981 before discovering that the course had been measured incorrectly and was 148 meters short of the marathon distance.
#7 Clarance DeMar4 of 11
DeMar won the Boston Marathon an unprecedented seven times throughout his career. Nicknamed Mr. DeMarathon, DeMar won the bronze medal at the 1924 Olympics.
#6 Khalid Khannouchi5 of 11
A four-time winner of the Chicago Marathon, Khannouchi set a world record in 1999 with a time of 2:05:42. In 2002, he became the first man in history to break 2:06 twice in the same year.
#5 Meb Keflezighi6 of 11
Keflezighi's silver medal at the 2004 Olympics was the first by an American man in the marathon since Frank Shorter's in 1976. Meb is also one of the select few Americans who have won the New York City (2009) and the Boston Marathon (2014).
#4 Deena Drossin Kastor7 of 11
Kastor was a bronze medal winner in the women's marathon at the 2004 Olympics in Athens. She holds the current American records in the marathon (2:19:36) and the half-marathon (1:07:34). She also won the Chicago Marathon in 2005 and the London Marathon in 2006.
#3 Bill Rodgers8 of 11
Rodgers won the Boston Marathon four times, including three straight victories from 1978 to 1980. He also won the New York City Marathon four consecutive times from 1976 to 1980. In 1979, Rodgers held the American record for the marathon at 2:09:27.
#2 Joan Benoit Samuelson9 of 11
Samuelson won gold at the 1984 Olympics in Los Angeles, the first year women were allowed to compete at the distance. Her times at the Chicago and the Olympic marathons are still the fastest times ever recorded by a woman. Her Boston Marathon time of 2:22:43 stood as the fastest time by an American woman for 28 years.
#1 Frank Shorter10 of 11
Frank Shorter's Olympic gold in the marathon in 1972 in Munich was the first medal by a U.S. runner at that distance since 1924. Shorter also won the silver medal in Montreal in 1976 and is still the only U.S. marathoner in history to win two Olympic medals at the marathon distance. His performances and his number one world ranking from 1971 to 1973 are credited for igniting the running boom in the 1970s.