Patriots' Day

Adapting the book was “one of the most difficult challenges I’ve ever had as a writer,” said Zetumer, whose credits include “Patriots Day,” a dramatization of the 2013 Boston marathon bombings.

At 6 a.m., race director Dave McGillivray sent out a group of about 20 from the Massachusetts National Guard that hikes the course on the state holiday of Patriots’ Day commemorating the start of the Revolutionary War.

Spectators were urged to take public transportation not just to the marathon, but to the annual Patriots’ Day Boston Red Sox game and a possible Boston Bruins playoff game, Cox said.

Like a lot of locals, Bill Evans grew up with the Boston Marathon — watching his brothers run the race or otherwise enjoying the day off from school on the Patriots’ Day holiday.

Doctors and first responders and others affected by the attacks are also drawn back to the race on the Massachusetts holiday of Patriots’ Day that commemorates the start of the Revolutionary War.