On the stormy night of August 29, 1776, the Continental Army faced capture or annihilation after losing the Battle of Brooklyn. The British had trapped George Washington’s forces against the East River, and the fate of the Revolution rested upon the shoulders of the soldier-mariners from Marblehead, Massachusetts. Serving side by side in one of the country’s first diverse units, they pulled off an “American Dunkirk” and saved the army by transporting it across the treacherous waters of the river to Manhattan.

In the annals of the American Revolution, no group played a more consequential role than the Marbleheaders. At the right time in the right place, they repeatedly altered the course of events, and their story shines new light on our understanding of the Revolution. As acclaimed historian Patrick K. O’Donnell dramatically recounts, beginning nearly a decade before the war started, and in the midst of a raging virus that divided the town politically, Marbleheaders such as Elbridge Gerry and Azor Orne spearheaded the break with Britain and shaped the nascent United States by playing a crucial role governing, building alliances, seizing British ships, forging critical supply lines, and establishing the origins of the US Navy.

The Marblehead Regiment, led by John Glover, became truly indispensable. Marbleheaders battled at Lexington and on Bunker Hill and formed the elite Guard that protected George Washington. Then, at the most crucial time in the war, the special operations–like regiment, against all odds, conveyed 2,400 of Washington’s men across the ice-filled Delaware River on Christmas night 1776, delivering a momentum-shifting surprise attack on Trenton. Later, Marblehead doctor Nathaniel Bond inoculated the Continental Army against a deadly virus, which changed the course of history.

White, Black, Hispanic, and Native American, this uniquely diverse group of soldiers set an inclusive standard of unity the US Army would not reach again for more than 170 years. The Marbleheaders’ chronicle, never fully told before now, makes The Indispensables a vital addition to the literature of the American Revolution.