According to the Harvard Alumni website, eight class marshals are elected every year. These marshals include the First and Second Marshals, who earn the most votes respectively and serve as essentially "class president" and "vice president," as well as six Program Marshals. The group's goal, along with the rest of the Senior Class Committee, is to "bring the Class together as a whole, connecting members of the Class of 2016 to each other and Harvard College by modeling and facilitating communication, participation, volunteerism, and giving among classmates." Their tasks among other things include organizing senior year events, such as all of the senior week activities, Class Day, the senior soiree, and class reunions (which if choosing a class marshal applies to you, probably makes you feel old). Basically, it appears that class marshals are responsible for a lot of the fun senior-specific events. It’s a little bit like what the Crimson Key is for freshmen, except also not.
Class marshals appear to have a lot of influence over the series of fun events for seniors' last moments here as well as post-grad get-togethers, so if you’re graduating this year, vote today for the First and Second Class Marshals!