When the Civil War began, 23-year-old Caspar Crowninshield of Boston, an 1860 graduate of Harvard College with influential family and political connections, sought a commission in the cavalry, but when no opening appeared, he accepted a commission in the 20th Massachusetts Infantry. Although Crowninshield had no formal military training, he was an intelligent and resourceful officer and a keen-eyed observer and reporter of all that happened around him. He escaped the disaster at Ball's Bluff by swimming the Potomac and found himself in temporary command of his regiment; all the senior officers present had been killed, wounded, or captured.

Intended as a "slight demonstration" on the south bank of the Potomac, the Battle of Ball's Bluff was a cruel introduction to war and its blunders for soldiers from Massachusetts. Bay State soldiers had died in the Civil War before Ball's Bluff, but there for the first time they played a major role in a battle. Two Massachusetts regiments made up part of the reconnaissance of Confederate positions along the upper Potomac near Leesburg, Virginia: the 20th Infantry Regiment--known as the "Harvard Regiment" because of its well-educated, socially-elite officers--and the 15th Infantry, recruited primarily out of Worcester County, Massachusetts. From the outset, almost everything that could go wrong did. Ball's Bluff was a natural trap--the Northern soldiers formed at the top of a steep cliff with their backs to the Potomac River, with only a few small boats to move reinforcements to the south bank, and to rescue survivors after the Union rout.

The 15th and 20th Massachusetts Infantry regiments were all but destroyed in the battle, together losing more than 500 men, including 84 killed or mortally wounded. Losses in the 20th included two grandsons of patriot Paul Revere who were taken prisoner, and future Supreme Court Justice Oliver Wendell Holmes, Jr., who was wounded.

"The Purchase by Blood: Massachusetts in the Civil War, 1861-1862": A New Exhibition at the Massachusetts Historical Society

"The Purchase by Blood," an exhibition of letters, photographs, recruiting posters, broadsides, maps, and prints highlights seven young Massachusetts officers united by bonds of kinship and friendship. The seven include William Lowell Putnam who died at Ball's Bluff and represent a network of descendants of three prominent Massachusetts families who had grown up together, attended the same schools, and, during the Civil War, served--and died--together as officers of two famous Massachusetts regiments, the 2nd and 20th Infantry. The exhibition is free and open to the public 7 October 2011-January 2012, Monday-Saturday, 10:00 AM-4:00 PM.