BOSTON (CBS) – Winning the Boston Marathon is one of the greatest individual athletic achievements in all of sports. That is, unless you won in 1918. World War I was underway, and with international athletic competitions being cancelled around the world, the Boston Marathon opted for a different format. 100 years later, the Military Relay is making a return to this year’s Boston Marathon, with local military members passing the baton. Watch how it all came about, and the unique spin on this year’s marathon in the video above.