A trio of medal contenders from the United States will run against strong teams from Kenya and Ethiopia Sunday morning in the Olympic marathon, a marquee event of the Summer Games.

As is tradition, the final day of the 2012 Summer Olympics is reserved for one of the world's most historic events: the marathon.

The marathon is one of the events from the original modern Games in 1896, a race won by Spyridon "Spyros" Louis in a rather impressive time (considering this was over 100 years ago) of 2 hours 58 minutes and 50 seconds. And the race has a particularly special history with London; for it was in the Big Smoke, where the city hosted the 1908 Games, that the length of the marathon was stretched from 26 to 26.2 miles, so the finish would pass by the viewing box of the Royal Family.

The 2012 edition of the race starts on The Mall and requires competitors to complete a loop of 2.2 miles, taking them to the River Thames, Houses of Parliament, and back up past Buckingham Palace. Then it's off toward the City of London for an eight-mile loop that is run three times before crossing the finish line back on The Mall (course map).

Unsurprisingly, the marathon is expected to be dominated by the East Africans. Of the 10 fastest marathons ever recorded, six of the men who own those times are in Sunday's field: Kenya's Wilson Kipsang (2:03:42) and Emmanuel Mutai (2:04:40); Ethiopia's Ayele Abshero (2:04:23), Getu Feleke (2:04:50) and Dino Sefir (2:04:50); and Eritrea's Samuel Tsegay (2:04:48).

There are three Americans in the field: Meb Keflezighi, Ryan Hall and Abdihakem Abdirahman. Meb won the silver medal in the 2004 Games, and more recently, won the U.S. Marathon Trials in January. Hall owns the fastest marathon time ever run by an American, a truly-world class 2:06:17 at 2008 London. Unfortunately for Hall -- and America's chances at a medal -- that only gets him the 69th spot on the all-time fastest marathons.

That's not to say a U.S. medal is completely impossible, of course -- especially since many think Hall has yet to run his best race -- but the Kenyas and Ethiopians are near-impossible to beat. How deep is the Kenyan team? Patrick Makau, the world-record holder, and Geoffrey Mutai, winner of both the Boston and New York Marathons in 2011, were left at home. Kipsang is considered by many to be the favorite, with his 2:03:42 coming at Frankfurt just last year.

What will be of particular interest to watch Sunday morning is how the men respond to a course that is full of twists and turns.

The defending gold medalist from Beijing, Samuel Wanjiru, died in 2011 after falling off a balcony at his home in Kenya, a death that still remains a mystery. His memory will be with the Kenyas on Sunday when they run to defend Wanjiru's title, the first Kenyan gold won in the marathon.

The race starts at 6 a.m. ET (11 a.m. in London) Sunday morning, and will be televised live on NBC (and online with NBC Live Extra).

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