Not all of them were there to run the full 26.2 miles on Saturday. There was also a half marathon and a 5K.
Brian Harvey, of Boston, won the main event in an unofficial time of 2 hours, 17 minutes, 56 seconds.
Liz Ryan, who grew up in Farmington but now lives in Boston, won the women's marathon in 2 hours, 45 minutes, 59 seconds.
Thousands of fans lined the course which wound through Hartford, East Hartford and South Windsor.
Organizers say last year's marathon generated more than $9.1 million for the local economy and they were expecting a similar impact from Saturday's event.