The Boston Marathon is an annual marathon sporting event hosted by the city of Boston, Massachusetts, on Patriots' Day, the third Monday of April. Begun in 1897 and inspired by the success of the first modern-day marathon competition in the 1896 Summer Olympics, the Boston Marathon is the world's oldest annual marathon and ranks as one of the world's most well-known road racing events. It is one of five members of the World Marathon Majors.

Today, the Boston Athletic Association (B.A.A.) manages this event. Amateur and professional runners from all over the world compete in the Boston Marathon each year, braving the hilly New England terrain and varying weather to take part in the race.

The event attracts an average of about 20,000 registered participants each year. In the 100th running of the Boston Marathon in 1996, the number of participants reached 38,000. While there are cash prizes awarded to the winners of the marathon, most of the runners participate for the accomplishment of having run the race at all.

April 20, 2009